In this extract from his memoir, Bill Hayes, partner of Oliver Sacks, recalls the neurologist’s unworldly charm, their remarkable stay with Björk in Iceland, and the dignity of Sacks’s final weeks

He wrote me a letter. That’s how we met. He had read my book, The Anatomist, in proof, and enjoyed it. (“I meant to provide a blurb,” but “got distracted and forgot.”) This was when I was still in San Francisco – early 2008. This was when people still wrote letters regularly and when one got a letter, sat down and wrote a letter back.

“Dear Mr Hayes – ”

“ – Dear Dr Sacks…”

Thus, a correspondence between O and me began.

A month later, I happened to be in New York and, at Oliver’s invitation, paid a visit. We had lunch at a cafe across the street from his office: mussels, fries, and several rounds of dark Belgian beer. We lingered at the table, talking, well into the afternoon. We found we had something other than writing in common: he, too, was a lifelong insomniac – indeed, from a family of insomniacs. (“It was understood at an early age that one could not sleep without sedation,” he told me wryly.)

I had not known – had never considered – whether he was hetero- or homosexual, single or in a relationship. By the end of our lunch, I hadn’t come to any firm conclusions on either matter, as he was both very shy and quite formal – qualities I do not possess. But I did know that I was intrigued and attracted. How could one not be? He was brilliant, sweet, modest, handsome, and prone to sudden, ebullient outbursts of boyish enthusiasm. I remember how O got quite carried away talking about 19th-century medical literature, “its novelistic qualities” – an enthusiasm I shared.

We stayed in touch. I sent him photographs I had taken in Central Park of bare tree limbs. I thought they looked like vascular capillaries. With his neurologist’s eye, he felt they looked like neurons.

“I am reminded of how Nabokov compared winter trees to the nervous systems of giants,” he wrote back.

I was sort of smitten, I had to admit.

Even so, that was that – for then. There was an entire country between us, not to mention 30 years’ age difference. My decision to move to New York more than a year later really had nothing to do with Oliver, and I certainly did not have a relationship in mind. I had simply reached a point in my life where I had to get away from San Francisco – and all the memories it held – and start fresh.

But once I moved, O and I started spending time together and quickly got better and better acquainted.

Not long after I moved to New York, Michael Jackson died. O had no idea who Michael Jackson was. “What is Michael Jackson?” he asked me the day after the news – not who but what – which seemed both a very odd and a very apt way of putting it, given how much the brilliant singer had transmuted from a human into an alien being. O often said he had no knowledge of popular culture after 1955, and this was not an exaggeration. He did not know popular music, rarely watched anything on TV but the news, did not enjoy contemporary fiction, and had zero interest in celebrities or fame (including his own). He didn’t possess a computer, had never used email or texted; he wrote with a fountain pen. This wasn’t pretentiousness; he wasn’t proud of it; indeed, this feeling of “not being with it” contributed to his extreme shyness. But there was no denying that his tastes, his habits, his ways – all were irreversibly, fixedly, not of our time.

“Do I seem like I am from another century?” he would sometimes ask me, almost poignantly. “Do I seem like I am from another age?”

“You do, yes, you do.”

For me, this was part of the fascination with him. I was seeing a few other men during my first summer in New York, but dates with O were completely different. We didn’t go to movies or to MoMA or to new restaurants or Broadway shows. We took long walks in the botanical garden in the Bronx, where he could expatiate on every species of fern. We visited the Museum of Natural History – not for the dinosaurs or special exhibitions but to spend time in the often empty, chapel-like room of gems, minerals, and, especially, the elements – O knew the stories behind the discoveries of every single one. At night, we might walk from the West Village to the East, O talking excitedly nonstop, to have a beer and burger at McSorley’s Old Ale House.

I learned that not only had he never been in a relationship, he had also never come out publicly as a gay man. But in a way, he’d had no reason to do so – he hadn’t had sex in three-and-a-half decades, he told me. At first, I did not believe him; such a monk-like existence – devoted solely to work, reading, writing, thinking – seemed at once awe-inspiring and inconceivable. He was without a doubt the most unusual person I had ever known, and before long I found myself not just falling in love with O; it was something more, something I had never experienced before. I adored him.

Facebook Twitter Pinterest Spring Shadows. Photograph: Bill Hayes

26 August 2012

I, listening to Björk on my iPod; O, reading and writing in his travel journal; We: drinking champagne on a flight to Reykjavík. I look over and see O making a list in his journal. He tells me he is writing out all the elements that are NOT present in the human body:

He

U

B

Be

Al

Si

Ar

Sg

Ti

V

Ni

Ga

Ge

As

Br

Kr

Rb

Sr

Y

Z

When I ask, he names each of them, following my finger as I go down the list. He interrupts himself at one point: “They like to be remembered and recited like this.” “They?” O nods. He could not look more delighted, and it’s not because of the alcohol. Listed separately, under the heading “No or infinitesimal”, are the exceptions. He goes on to explain the difference between organic and nonorganic chemistry. I do not – and expect I never will – understand half of what he is saying.

28 August 2012

Björk invited us to her home in Reykjavík for lunch – a remarkable afternoon; O said it best: “Everything was unexpected.” The two met a couple of years ago when Björk asked Oliver to appear in a BBC documentary about music, but they had never spent time together socially. And in fact, O knew very little about her work up until shortly before we made this trip. I got a DVD compilation of her music videos and conducted a crash course in Björk for him. O sat on the edge of his bed, inches from the TV screen, as he needs to in order to hear properly, and watched without stirring, mesmerised especially by the visuals, for 90 minutes. Because of his face blindness, which makes it difficult for O to recognise people not only on the street but also in movies and on TV, he’d sometimes ask, “Is that Björk?” or, “Which one is Björk?” A swan dress one minute, robotic gear the next, her constant changing of costumes and hairstyles utterly confounded him, but he was deeply impressed by her artistry.

We pulled into the driveway at the back of Björk’s home and I saw her through the kitchen window. She looked to be in the middle of a task, concentrating. A simple hedge fenced the house. There was a child-sized table and chairs in the front yard, the setting for a tea party. We didn’t see a path, so we parted a hedge awkwardly and made our way to the front door. She answered. In my memory, she curtsied. Of course she didn’t, but her air of modesty and respect in greeting O had that feeling. She ushered us into the dining room, where a table was set.

Björk’s hair was up, held by a barrette with blue feathers. She wore a simple tunic made from several different kinds of coloured and patterned fabric; she may have made it herself. She wore white pants under the tunic and wedge sandals. Her face: unlined, no makeup, pretty; eyes the color of jade; lush, jet-black eyebrows, shaped like two feathers.

Björk urged us to sit and eat. The chairs were carved from tree stumps. The tablecloth was embroidered with seashells. On the table: warm, salted mixed nuts in tiny dishes. Almost immediately, she brought out a steaming pan of baked trout, a salad and a bowl of boiled potatoes – “I like it with the skins left on,” she said, almost apologetically, “don’t you?” O and I nodded.

Conversation was lively. We talked about Iceland, about Oliver’s new book, Hallucinations; about her CD, Biophilia, and her new projects. She told us that she’d recorded Biophilia (its name inspired by Oliver’s Musicophilia) in the lighthouse I’d spotted the night before when I was chasing down the sunset. Björk said she had a calendar in the kitchen with the time for the tide going in and out, so they would know when they could get to the lighthouse – and how long they would be “stuck” there while the tide was in. She laughed. “It was really, really good, because it forced me to work; I couldn’t leave if I wanted to.”

After eating, Björk led us from the table, through a little door, and to the stairs. These were not stairs in any conventional way. Oliver – ever the naturalist – knew exactly: “Why, these are basalt stones! This looks like a stairway carved out of a wall of basalt!” Björk nodded. Adding to this remarkable sight: the railing in the winding stairway was made of whale rib bones. Björk smiled and helped Oliver up. “And this,” – she pointed to the shimmering lamp hanging overhead, dropping into the stairwell – “actually my daughter and I made it out of mussel shells. It wasn’t supposed to be permanent, but… we like it.”

She wandered into an upper room, and we followed. There, she showed us two custom-made instruments, a celeste and what looked like a harpsichord. Both had been modified somehow through instructions from a programme on her Mac. I could tell that O was completely lost as she explained how this worked. Yet it was then, right then, that I realised how much she and O were alike – fellow geniuses, incredibly, intuitively brilliant – while being at the same time such an unlikely pair of friends.

Back downstairs, Björk brought out a gooseberry pie, with berries picked from her own trees. She’d made it with her daughter the night before. “As she was the cook, of course she had to have the first piece,” she said, pointing out the missing wedge. She served it topped with fresh, plain skyr, which has a sour bite to it – along with coffee and tea. The tea set was out of Alice in Wonderland – each cup literally half a cup, sliced in half. “I’ve learned that these are for right-handed people, these teacups,” she says, “or I learn who is left-handed by watching them try to drink from them.” She giggled.

We finished the pie. I looked at Oliver’s watch and saw that it was almost 3.30; we’d been here three hours. Oliver signed an advance copy of Hallucinations –“You will be the only person in all of Iceland with this book” – and I gave her a copy of one of mine. “For Björk, with gratitude,” I signed it.

30 December 2012

On a red-eye to Reykjavík for New Year’s Eve: Leaving New York, the city looked embroidered in gold thread. Now, clouds and stars, and what sounds like a hymn: “Craving miracles…” Björk sings.

1 January 2013

Supper of skyr, biscuits and tea in our tiny hotel room. Recovering. Snow falling. Last night, a New Year’s Eve dinner at Björk’s, was like being safely in the middle of a very happy war; a huge bonfire on the beach across the street from her home encircled by people singing; fireworks going off in every direction, from every home, all night long, and culminating in a chaotically beautiful, or beautifully chaotic, fireworks display at midnight in the town square. As if the sky were full of shooting stars. As the church bells pealed 12 times. As the ground was snow-covered, white, the floor of a cloud. As everyone kissed and hugged one another. Bottles of champagne and brennivín, an Icelandic schnapps – clear and strong.

17 February 2013

Oliver and I went to a small chamber orchestra concert at the American Irish Historical Society, a jewel box of a building directly across the street from the Metropolitan Museum. He knows the Irish gentleman who organises these concerts, Kevin. They feature students from Juilliard. Very intimate. Unpretentious. Free of charge. A handful of people in folding chairs – maybe 40. Kevin had saved seats for O and me in the front row. Just as he was making his introductions, a woman rushed in by herself and plopped on to the cushy rose-coloured sofa right next to our seats: Lauren Hutton, the model from the 70s: I recognised her instantly by her gap-toothed smile and slightly crossed eyes. Now in her late 60s, still beautiful, her face naturally lined. And, one couldn’t help but notice, she had a big bruiser of a black eye.

The concert began with no further ado, and we all sat back and enjoyed the programme – Brahms, Haydn, Ravel – by these enchanting musicians.

With the final note, Lauren Hutton was the first to pop up and give the trio a standing ovation. “Do you have a fan club?” she yelled above the clapping; it was a little startling, like someone yelling in a church. “I’m starting your fan club. You’re fantastic, you’re going places!” The musicians bowed shyly and departed.

There was a small reception afterwards. Nothing fancy – two bottles of San Pellegrino and a couple bottles of wine – but no bottle-opener. O and I were talking with Kevin when Lauren Hutton walked up to us: “Do one of you kind gentlemen have an opener? Even a knife would do – I could pry it open with a penknife.”

“Why don’t you use your teeth?” I said to her.

She laughed and smiled that famous gap-toothed smile. “I could. I could have once, but…” she wandered off. The bottle got opened somehow. Eventually she circled back and poured water for everyone. She overheard Oliver talking to Kevin about his new book, Hallucinations, which was coming out in a couple weeks. Lauren leaned across the table and listened intently.

“Hey doc, you ever done belladonna?” she asked. “Now there’s a drug!”

“Well, as a matter of fact, yes, I have,” and he proceeded to tell her about his hallucinations on belladonna. They traded stories. Eventually she began to figure out that this wasn’t his first book.

“Are you – are you Oliver Sacks? The Oliver Sacks?” Oliver looked both pleased and stricken.

“Well, it is very good to meet you, sir.” She sounded like a southern barmaid in a 50s western. But it wasn’t an act. “I’ve been reading you since way back. Oliver Sacks – imagine that!”

Oliver, I should note, had absolutely no idea who she was, nor would he understand if I had pulled him aside and told him.

Fashion? Vogue magazine? No idea…

The two of them hit it off. She was fast-talking, bawdy, opinionated, a broad – the opposite of Oliver except for having in common that mysterious quality: charm.

Somewhere along the way, she explained the black eye: a few days earlier, she had walked out of a business meeting at which she’d learned that she had been “robbed” of a third of everything she’d ever earned, and in a daze walked smack into a scaffolding pipe at eye level on the sidewalk. She didn’t seem too bothered by it: shit happens.

I looked up and saw that the room was empty by now but for Kevin and us.

“Well, gentlemen, I’m going downtown. Share a cab?”

“Uh, we have a car,” I said.

“Even better. Much more civilised. I’m downtown.”

How could one refuse? “Let’s go, shall we?” I said. Lauren Hutton offered Oliver an arm and we walked slowly to the parking garage. I pushed things out of the way in the back seat; she tossed in her handbag, and dove in. She immediately popped her head between our seats – the three of us were practically ear-to-ear.

Her incredible face blocked my rearview mirror. When O took out his wallet to give me a credit card for the parking, she spotted the copy of the periodic table he carries in lieu of a driver’s licence. This prompted a series of questions about the periodic table, the elements, the composition of the very air we were breathing. A dozen questions led to a dozen more, like a student soaking up knowledge. We talked about travels – Iceland, Africa – and Plato, Socrates, the pygmies, William Burroughs, poets… She was clearly intensely curious, life-loving, adventurous. In passing, she said something about having been a model – “The only reason I did it was so I could make enough dough to travel” – but otherwise didn’t say anything about that part of her life. Traffic was thick, so it took quite a while to get downtown.

Eventually, we reached her address, or close enough.

“Well, gentlemen, it has been a true pleasure. I cannot thank you enough. This is where I exit. Goodbye – for now.” And she was gone, as suddenly as she’d arrived. Oliver took a breath as we headed west and home. “I don’t know who that was, but she seems like a very remarkable person.”

12 January 2015

Got back last night from St Croix in the US Virgin Islands – a birthday trip. I turned 54 (equivalent to the atomic number for xenon, so O gave me four xenon flashlights). O did not feel well much of the time – nauseated, tired, slept a lot. We almost cancelled the trip, last minute. Two nights before we left, he told me he had “dark urine”. I was sceptical – he’s hypochondriacal even on good days, as he is the first to admit. But I could see he was worried, talked him into peeing into a clear glass so I could check, and was startled when he brought it into the kitchen; his urine was the colour of Coca-Cola. It seemed to clear up some while we were in St Croix. Even so, he had made a doctor’s appointment before leaving for the trip.

Later…

O just returned from his GP, who thinks he has some kind of gallbladder inflammation, maybe gallstones. Did an ultrasound, but they’re running more tests.

15 January 2015

O’s doctor phoned: “peculiar findings” re: Cat scan yesterday. So: am taking him to see a radiologist at Sloan Kettering. They want to see him this afternoon.

Sloan Kettering is a cancer hospital, but cancer had not entered my mind. I was still banking on the possibility of gallstones; I thought, at worst, Oliver might have to have his gallbladder removed. I remember the doctor entering the consulting room with a young medical fellow (he was from Italy, I think), and how nervous the young man looked. The doctor got right to it and told us that he had carefully reviewed the Cat scan and, although a confirmatory biopsy would have to be performed, he was 90% sure of the diagnosis and said he had some “tough” news. I remember that word, “tough”. He asked Oliver if he’d like to see the Cat scan. Oliver said yes, of course, and he flipped on the computer monitor.

Later he told me that he knew instantly what the scan said. I did not, and I was stunned when the radiologist explained that what we were looking at was a recurrence of the uveal melanoma Oliver had had nine years earlier – a cancer arising from the pigment cells in his right eye; over time, it had metastasised to his liver, which was now “riddled like Swiss cheese” with tumours. He enlarged the image on the monitor, so the white spots – the tumours – looked as large as those made by a hole punch. In cases like this, with a possibility of the cancer spreading, and at Oliver’s age, the doctor said, neither a liver resection nor a liver transplant would be possible. What has stuck with me so clearly is how calmly Oliver took this news. It was as if he was expecting it, as perhaps he was. He sort of tilted his head and stroked his beard and asked about the prognosis, and the doctor said: “Six to 18 months.”

“And there’s no effective treatment?”

The doctor didn’t say no, but he didn’t say yes. He explained what could be done, that everything possible would be done, an oncology team was already in place, he’d just gotten off the phone with a specialist, and so on, but Oliver cut him off. He said he was not interested in “prolonging life just for the sake of prolonging life”. Two of his brothers had died of different forms of cancer, and both had regretted undergoing horrid chemotherapy treatments that had done nothing but ruin their last months.

“I want to be able to write, think, read, swim, be with Billy, see friends, and maybe travel a bit, if possible.” Oliver added that he hoped not to be in “ghastly pain” or for his condition to become “humiliating”, and then he fell silent.

The next day, we went swimming at noon, as we always did on Fridays, and then spent a quiet weekend together, taking walks, reading, listening to music, going to the open-air market at Abingdon Square, cooking, both of us trying to absorb the overwhelming news. Oliver consulted with a few colleagues, including the ophthalmologist who had treated his cancer years before; he had had a chance to look at the Cat scan, too. Recurrences such as this were considered extremely rare, yet the consensus seemed to be that the preliminary diagnosis was most likely correct and that treatment options were few.

Over the weekend, Oliver mentioned a few times that he was considering writing “a little piece” about receiving his diagnosis. And on Sunday night, after we had made dinner and cleared the dishes, he took up a small notepad and his fountain pen. “Well, let’s see…” He paused. “I suppose I want to begin by saying that a month ago, I felt that I was in good health. But… now my luck has run out…”

“Hold it,” I interrupted, “let me get a pen.” I did so, and a notepad, and I scribbled what he had just said. “OK, keep going.” From there, Oliver dictated the entire essay, nearly verbatim to the version that would eventually appear in the New York Times.

He spent several days tinkering with it but then he set it aside. Oliver worried that his feelings were perhaps too raw, and felt it was too soon to publish it, given that most of his friends and family members did not yet know his news.

In lieu of any experimental treatments, Oliver made the decision to go ahead with a surgical procedure called an embolisation, which would cut off blood supply to the tumours in his liver and therefore kill them off – temporarily (they would inevitably return, he was told). Dramatically lowering the “tumour burden” held the promise of offering him several more months of active life. As we waited in the hospital for him to be admitted for surgery, Oliver suddenly turned to Kate [Edgar, Sacks’s long-time friend and collaborator] and me and said he felt the time was right to send the piece over to the New York Times. Neither of us questioned him; we just said, OK. Kate emailed the essay to our mutual editor at the Times, and we heard back almost immediately: They wanted to run the piece the next day. We asked for one extra day – to get Oliver safely through the procedure first – and they agreed. Oliver’s essay My Own Life was scheduled for publication on 19 February 2015.

17 February 2015

In post-surgery recovery: cutting off blood supply to the tumours in the liver may sound somewhat benign, but the body revolts with full force against such an intrusion. O repeatedly tears off his hospital gown because he is in so much pain that even the thin cotton material causes discomfort. The young female nurses act scandalised by this and keep trying to cover him up. At one point, O yells out in exasperation: “If one can’t be naked in a hospital, where can one be naked?!” I hear a nurse in the hallway join me in laughter. I cover his genitals with a washcloth when the morphine finally kicks in and he falls asleep.

27 February 2015

I brought O a few of the letters and emails written in response to his New York Times essay. I: “How’d it feel to read those?” O: “Good!” I: “You have about 800 more to go.” O: “I’d like to see all of them.”

22 April 2015

O: “The most we can do is to write – intelligently, creatively, critically, evocatively – about what it is like living in the world at this time.”

7 July 2015

O, proudly, playing a new Schubert piece, and with great flair demonstrating how it requires “crossed hands”. I am quite amazed and impressed, and I clap.

8 July 15

The day before O’s 82nd birthday, and we got bad news with his latest Cat scan – bad – much worse than expected. Not only have the tumours regrown, the cancer has spread: kidneys, lungs, skin. O wants to go ahead with his birthday party, and doesn’t want people to know. “Auden always said one must celebrate one’s birthday,” he says.

9 July 2015

O’s birthday: at his party – O asks me to go get the bottle of 1948 Calvados – a rare brandy given to him as a gift years ago and sealed in a wooden box. I open it for him. I: “Do you want a glass?” O: “No,” he says, and takes a swig, eyes closed. “Lovely,” he pronounces and looks around the room. “Who would like some?” Later, he tells me he’d forgotten that he had left the Calvados to a friend in his will.

13 July 2015

Very, very tired, I did the dinner dishes quickly, gathered my things, and earlier than usual, told Oliver I was heading to bed and said good night. But as I headed for the bedroom, O called to me from his desk, “Do you know why I love to read Nature and Science every week?” I turned. “No,” I shook my head. I was almost confused; this seemed such a non sequitur. “Surprise – I always read something that surprises me,” he said.

25 July 2015

In the country: O is finishing one essay, working on two others – at least two others. “How’s the writing going?” I ask, waking from a nap. He smiles mischievously. “I meant to stop, but I couldn’t.” And he goes back to it. I watch. He doesn’t have a fancy desk here; it’s just a folding table. All he needs is a pad and his fountain pen and a comfortable chair.

Later, we go for a swim. The water in the pool is a bright emerald green, caused by an excess of copper and iron in the well.

“You are swimming in the elements,” I tell O, “swimming in a pool of copper.”

“Lovely,” he murmurs, doing his backstroke.

1 August 2015

He plays Beethoven – he never used to – long, haunting pieces, complex pieces – whereas he used to only play Bach preludes, and in stops and starts.

10 August 2015

O is working on a new piece: Sabbath. Every now and then, a little request comes, always phrased politely: “If you would be so kind: look up something for me on your little box?” “Little box” is his name for an iPhone, a name he finds too ugly to pronounce, to speak. “It’s not even a word,” as he points out, “it’s a brand.” Sometimes he calls the phone my “communicator”, as if out of Star Trek. Today, he wants me to look up the meaning of the Latin “nunc dimittis”. As is almost always the case with O, it wasn’t necessary: he’d had the definition exactly right in the first place: nunc dimittis is “the final song in a religious service”.

16 August 2015

“I say I love writing, but really it is thinking I love – that rush of thoughts – new connections in the brain being made. And it comes out of the blue.” O smiled. “In such moments: I feel such love of the world, love of thinking…”

23 August 2015

“What are your wishes, Dr Sacks?” said the hospice nurse. “How would you like to pass?” “At home,” answered O in a clear, steady voice, “with no pain or discomfort, and with my friends here.”

28 August 2015

O, who has had no appetite, suddenly asked to have smoked salmon and Ryvita for lunch. He insisted we get him out of bed, into his “dressing gown”, take him to his table, and “to see my piano”. We brought a plate to him: with incredible dignity, and slowness, he carefully cut a single piece at a time. He could only eat three bites. And when I suggested something sweet – some ice cream? He said: “No, a pear.” He had one slice then asked that we take him back to bed.

29 August 2015

I am at his side, in his bedroom, where Kate and I have been keeping a special watch since 5.30am. That’s when Maurine (our hospice nurse) woke me in the other room: “Billy, come now – his breathing has changed.” It has slowed to just three or four breaths per minute – long silences in between. He is no longer conscious. He is stretched out on his bed diagonally and looks comfortable. Maurine, who has been at the side of many patients as they die, tells us this is the last phase, but that it could go on for many hours, days maybe. A little while ago, I looked around the room, crowded with bedsheets, towels, pads, medications, an oxygen tank and other medical equipment, and I began clearing it out, all of it. First, I brought in stacks of all of O’s books, cleared a bedside table, and put them there. I brought in a cycad plant and a fern. Kate joined me, and we cleared more space, making room on another table for some of O’s beloved minerals and elements, his fountain pens, a ginkgo fossil, his pocket watch. Elsewhere, a few books by his heroes – Darwin, Freud, Luria, Edelman, Thom Gunn – and photos – his father, Auden, his mother as a girl with her 17 siblings, his aunts and uncles, his brothers. We brought in flowers, candles. I am heartbroken but at peace. Last night, before getting some sleep, I came in to see if he needed anything.

“Do you know how much I love you?” I said.

“No.” His eyes were closed. He was smiling, as if seeing beautiful things.

“A lot.”

“Good,” O said, “very good.”

“Sweet dreams.”

Bill Hayes Q&A: ‘Conversations and scenes jumped off the page’

Facebook Twitter Pinterest Oliver Sacks, left, and Bill Hayes in 2015. Photograph: Corbis

What made you publish your diaries? Some of the entries are very intimate and personal… why did you want to make them public?

I didn’t expect to. I had signed a contract to write a book about New York a long time before Oliver got his diagnosis and initially I had no expectation that I was even going to write about us. But things changed after his death and I began to think about how I would write about my life in New York, my relationship with New York City and my relationship with Oliver. It was then that I went back to my journal, which I had started at Oliver’s urging a few weeks after I moved here in 2009. Conversations and scenes just jumped off the page and I realised they could be much more effective at chronicling our lives than if I were to write a more traditional narrative.

The entries that follow the diagnosis of Oliver’s cancer are terribly affecting. How difficult were those days for you?

Extremely difficult, heartbreaking at times. But it wasn’t a first experience for me [Hayes cared for his previous partner through several Aids-related illnesses before losing him to a heart attack]. As a gay man living in San Francisco in the early 1990s, I had very deep and intimate experience of the Aids epidemic, caring for and losing friends and co-workers at the San Francisco Aids Foundation. That’s not to say it made it easier, exactly, caring for Oliver but dying was something I knew about.

How would Oliver have felt about Insomniac City?

I think he would have been delighted and proud. Oliver published his autobiography, On the Move, in May 2015, three months before his death. It’s very candid and open about his sexual identity and about our relationship. Prior to that, Oliver had never spoken or written at all about his private life and his decision to do so gently opened a door, allowing me to write about my life with him in a way I am not sure I would have or could have had he not done that.

How would you describe Oliver’s legacy to the world?

I think there are several legacies. I think he opened up for the world and for all of us conversations about neurodiversity and neurological conditions and how people adapt to them, everything from autism to Tourette syndrome to blindness. I think he also left an amazing legacy in his writing about mortal illness and facing death in his columns in the New York Times. That was, I think, a very generous and gracious act in his final year. And his final legacy is that, while on one level my book is about me reinventing myself in middle age, there’s another story there about Oliver Sacks reinventing himself, in his 70s. And I love that. At age 75, he opened his heart up and fell in love, started a new romantic and domestic life with another person – with me – and continued to work so productively – all of which made being old seem adventurous and fun.

What do you miss most about Oliver?

His companionship. I hope the reader gets a sense of what our relationship and conversations were like. We talked and laughed a lot. He was very funny and liked wordplay and puns. He could be very self-deprecating and eccentric. So most of all I miss the comfort of his company and the laughter.

Interview by Lisa O’Kelly

• Extract from Insomniac City: New York, Oliver, and Me by Bill Hayes (Bloomsbury £16.99). To order a copy for £14.44 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99

• Bill Hayes will be signing copies of Insomniac City on Monday 3 April at the London Review Bookshop, London WC1, and on Tuesday 4 April at Gay’s the Word, also London WC1. He will be giving a talk on 4 April to the How to Academy, at the Condé Nast College of Fashion & Design, London W1