I’m the youngest by far of five children. My mother was 35 when she conceived me in 1951, so chagrined by this chronological indiscretion that she tried to hide the pregnancy from her sister. My mortified oldest brother didn’t want to tell his high-school friends that a new baby was on the way, but it was a small town. Word spread.

My mother’s age and my late arrival in the family felt burdensome to me too, especially when I started school in 1957 and met my classmates’ mothers. They were still having babies! Still piling their children into cars and heading off to picnics at the river or hikes into the lava-capped, wild flower-rampant plateau outside town. They still had to mediate hair-pulling and toy-snatching. But by the time I started first grade, my siblings were gone, the oldest three to college and the youngest to a residential school four hours away, and we went from a very noisy household to a very quiet one.

My family has told me stories about those years before everything changed. How my oldest brother nicknamed me ‘Ubangi’ because my hair grew in tight fat curls close to my head. How my other brother liked to ambush me around corners with a toy crocodile because it never failed to make me shriek in terror. How my oldest sister carried me around like a kangaroo with her joey. But I can offer very few stories of my own from those early years.

My strongest recollection is a constant straining to be with my brothers and sisters. I remember having to go to bed when it was still light out, kicking at the sheets as I listened for their voices coming down the hall or through the windows from the back yard. Sometimes I could smell popcorn. The next morning, I’d search the living room rug for their leftovers and roll the unpopped kernels around in my mouth. I do remember that, probably because it was something that played out night after night – our father loved popcorn.

Several years ago, I thought I might have the chance to recover that lost past when we were all tightly clustered together in one house. My brothers had driven to Bucks Lake up in the Sierras of northeastern California where, until I was around three years old, our family had leased a house every summer to escape the Sacramento Valley heat. They found our old cabin unchanged. Even a table built by a local sawmill was still in the living room. They knocked on the door and, weirdly enough, my younger brother knew the current lessee. He invited them in and then invited the rest of us back for a look.

With our father, we set off a few months later, up highways that narrowed into dusty roads through dark pines and past bright stony summits. When we got to the cabin, my siblings scattered to claim their favourite outdoor spots, but I was rooted near the car, struck by how much this place differed from what I thought I remembered.

I recalled that the water was a long walk across a sandy beach from the house; I had an image of my mother standing on that wide beach, her dress whipped by the wind, her hand cupped near her mouth. But the pebbled shoreline was just a few feet away. I recalled the spine of a dam jutting from the water not far from the house, a perilous and sudden cliff at the edge of the lake that my siblings had once ventured too close to. But even though the lake is a man-made one, the dam wasn’t visible from the house. I followed my father inside, where the tininess of the kitchen fascinated him. He kept opening cabinet doors and laughing as they banged each other in the narrow aisle. ‘Mother just hated this kitchen!’ he said. ‘She always made big breakfasts – eggs and sausage and pancakes – and as soon as she finished cleaning up, you kids would come running back in the house wanting lunch.’

Kristin Ohlson being looked after by elder sister Sue.

I didn’t remember that. I didn’t remember the table. I didn’t remember anything about the place. My siblings tugged me through the house, pointing out where everyone had slept – they said I had been in a little alcove in the hallway, though I recalled staying in my parents’ room and watching them sleep in the early morning light. They pointed out other features tied to the life that we all lived in the cabin, eager for me to remember, but there was nothing. I even dropped to my knees and circled the living room at toddler level, peering at dusty windowsills and sniffing at the knotholes in the pine walls and running my fingers over the floorboards. Nothing.

I now know that it would have been unusual for me to remember anything from that time. Hardly any adult does. There is even a term for this – childhood amnesia, coined by Sigmund Freud in 1910 – to describe the lack of recall adults have of their first three or four years and our paucity of solid memories until around the age of seven. There has been some back and forth over a century of research about whether memories of these early years are tucked away in some part of our brains and need only a cue to be recovered. That’s what I was hoping when I revisited our old cabin with my siblings. I intended to jostle out a recalcitrant memory with the sights, sounds, smells and touch of the place. But research suggests that the memories we form in these early years simply disappear.

Freud argued that we repress our earliest memories because of sexual trauma but, until the 1980s, most researchers assumed that we retained no memories of early childhood because we created no memories – that events took place and passed without leaving a lasting imprint on our baby brains. Then in 1987, a study by the Emory University psychologist Robyn Fivush and her colleagues dispelled that misconception for good, showing that children who were just 2.5 years old could describe events from as far as six months into their past.

But what happens to those memories? Most of us assume that we can’t recall them as adults because they’re just too far back in our past to tug into the present, but this is not the case. We lose them when we’re still children.

The psychologist Carole Peterson of Memorial University of Newfoundland has conducted a series of studies to pinpoint the age at which these memories vanish. First, she and her colleagues assembled a group of children between the ages of four and 13 to describe their three earliest memories. The children’s parents stood by to verify that the memories were, indeed, true, and even the very youngest of the children could recall events from when they were around two years old.

if the memory was a very emotional one, children were three times more likely to retain it two years later

Then the children were interviewed again two years later to see if anything had changed. More than a third of those age 10 and older retained the memories they had offered up for the first study. But the younger children – especially the very youngest who had been four years old in the first study – had gone largely blank. ‘Even when we prompted them about their earlier memories, they said: “No, that never happened to me,”’ Peterson told me. ‘We were watching childhood amnesia in action.’

In both children and adults, memory is bizarrely selective about what adheres and what falls away. In one of her papers, Peterson trots out a story about her own son and a childhood memory gone missing. She had taken him to Greece when he was 20 months old, and, while there, he became very excited about some donkeys. There was family discussion of those donkeys for at least a year. But by the time he went to school, he had completely forgotten about them. He was queried when he was a teenager about his earliest childhood memory and, instead of the remarkable Greek donkeys, he recalled a moment not long after the trip to Greece when a woman gave him lots of cookies while her husband showed the boy’s parents around a house they planned to buy.

Peterson has no idea why he would remember that – it was a completely unremarkable moment and one that the family hadn’t reinforced with domestic chitchat. To try to get a handle on why some memories endure over others, she and her colleagues studied the children’s memories again. They concluded that if the memory was a very emotional one, children were three times more likely to retain it two years later. Dense memories – if they understood the who, what, when, where and why – were five times more likely to be retained than disconnected fragments. Still, oddball and inconsequential memories such as the bounty of cookies will hang on, frustrating the person who wants a more penetrating look at their early past.

To form long-term memories, an array of biological and psychological stars must align, and most children lack the machinery for this alignment. The raw material of memory – the sights, sounds, smells, tastes and tactile sensations of our life experiences – arrive and register across the cerebral cortex, the seat of cognition. For these to become memory, they must undergo bundling in the hippocampus, a brain structure named for its supposed resemblance to a sea horse, located under the cerebral cortex. The hippocampus not only bundles multiple input from our senses together into a single new memory, it also links these sights, sounds, smells, tastes, and tactile sensations to similar ones already stored in the brain. But some parts of the hippocampus aren’t fully developed until we’re adolescents, making it hard for a child’s brain to complete this process.

‘So much has to happen biologically to store a memory,’ the psychologist Patricia Bauer of Emory University told me. There’s ‘a race to get it stabilised and consolidated before you forget it. It’s like making Jell-O: you mix the stuff up, you put it in a mould, and you put it in the refrigerator to set, but your mould has a tiny hole in it. You just hope your Jell-O – your memory – gets set before it leaks out through that tiny hole.’

In addition, young children have a tenuous grip on chronology. They are years from mastering clocks and calendars, and thus have a hard time nailing an event to a specific time and place. They also don’t have the vocabulary to describe an event, and without that vocabulary, they can’t create the kind of causal narrative that Peterson found at the root of a solid memory. And they don’t have a greatly elaborated sense of self, which would encourage them to hoard and reconsider chunks of experience as part of a growing life-narrative.

Frail as they are, children’s memories are then susceptible to a process called shredding. In our early years, we create a storm of new neurons in a part of the hippocampus called the dentate gyrus and continue to form them throughout the rest of our lives, although not at nearly the same rate. A recent study by the neuroscientists Paul Frankland and Sheena Josselyn of the Hospital for Sick Children in Toronto suggests that this process, called neurogenesis, can actually create forgetting by disrupting the circuits for existing memories.

the mother engages the child in a lively conversation about events, always passing the baton of remembering back to the child

Our memories can become distorted by other people’s memories of the same event or by new information, especially when that new information is so similar to information already in storage. For instance, you meet someone and remember their name, but later meet a second person with a similar name, and become confused about the name of the first person. We can also lose our memories when the synapses that connect neurons decay from disuse. ‘If you never use that memory, those synapses can be recruited for something different,’ Bauer told me.

Memories are less vulnerable to shredding and disruptions as the child grows up. Most of the solid memories that we carry into the rest of our lives are formed during what’s called ‘the reminiscence bump’, from ages 15 to 30, when we invest a lot of energy in examining everything to try to figure out who we are. The events, culture and people of that time remain with us and can even overshadow the features of our ageing present, according to Bauer. The movies were the best back then, and so was the music, and the fashion, and the political leaders, and the friendships, and the romances. And so on.

Of course, some people have more memories from early childhood than others do. It appears that remembering is partly influenced by the culture of family engagement. A 2009 study conducted by Peterson together with Qi Wang of Cornell and Yubo Hou of Peking University found that children in China have fewer of these memories than children in Canada. The finding, they suggest, might be explained by culture: Chinese people prize individuality less than North Americans and thus may be less likely to spend as much time drawing attention to the moments of an individual’s life. Canadians, by contrast, reinforce recollection and keep the synapses that underlie early personal memories vibrant. Another study, by the psychologist Federica Artioli and colleagues at the University of Otago in New Zealand in 2012, found that young adults from Italian extended families had earlier and denser memories than those from Italian nuclear families, presumably as a result of more intense family reminiscence.

But it doesn’t necessarily take a crowd of on-site relatives to enhance a child’s recollection. Bauer’s research also points to ‘maternal deflections of conversation’, meaning that the mother (or another adult) engages the child in a lively conversation about events, always passing the baton of remembering back to the child and inviting him or her to contribute to the story. ‘That kind of interaction contributes to the richness of memory over a long period of time,’ Bauer told me. ‘It doesn’t predict whether a given event will be remembered, but it builds a muscle. The child learns how to have memories and understands what part to share. Over the course of these conversations, the child learns how to tell the story.’

Borrowing Bauer’s Jello-O analogy, I’ve always suspected that my mother had a tinier hole in her Jell-O mould than mine, which allowed her to retain information until it was set into memory. She seemed to remember everything from my childhood, from my siblings’ childhoods, and from her own first six years. Intensely, she recalled the fight between her mother and father, when her mother wound up getting knocked out cold and her father forced her to tell visiting neighbours that his wife was sleeping. The day my grandmother packed up my mother and her sister and moved them from Nebraska to Nevada, with their unwanted household goods strewn across their lawn for the townspeople to pick through and haggle over. The day the doctor took out my mother’s appendix on the kitchen table. The day she wet her pants at school and the nuns made her walk home in weather so cold that her underwear froze. I wondered if her memories were so sharp because these were all terrible events, especially compared with my presumably bland early years.

I now suspect that my mother’s ability to tell the story of her early life also came from the constellation of people clustered at the centre of it. Her young mother, bolting from a marriage she was pressured into and retreating to her brother’s crowded house, her two girls held close. And her sister, three years older, always the point and counterpoint, the question and response. My mother and her sister talked their lives over to such an extent that it must have seemed as if things didn’t really happen unless they had confided them to each other. Thus, ‘Don’t tell Aunt Helen!’ was whispered in our house when something went wrong, echoed by ‘Don’t tell Aunt Kathleen!’ in our cousins’ house when something went amiss there.

I might have a very large hole in my Jell-O mould, but I also wonder if our family’s storytelling and memory-setting apparatus had broken down by the time I came along. My brothers and sisters doted on me – I’m told this and I believe it – but it was their job to be out in the world riding horses and playing football and winning spelling bees and getting into various kinds of trouble, not talking to the baby. And sometime between my being born and my siblings leaving, our mother suffered a breakdown that plunged her into 20 years of depression and agoraphobia. She could go to the grocery store only with my father close to her side, steering the cart, list in hand. Even when she went to the beauty salon to have her hair cut and styled and sprayed into submission, my father sat next to her reading his Wall Street Journal as she cured under one of those bullet-head dryers. When we were home, she spent a lot of time in her room. No one really knows when my mother’s sadness and retreat from the world began – and she’s not around to tell us now – but it might have started when I was very young. What I remember is silence.

Our first three to four years are the maddeningly, mysteriously blank opening pages to our story of self. As Freud said, childhood amnesia ‘veils our earliest youth from us and makes us strangers to it’. During that time, we transition from what my brother-in-law calls ‘a loaf of bread with a nervous system’ to sentient humans. If we can’t remember much of anything from those years – whether abuse or exuberant cherishing – does it matter what actually happened? If a tree fell in the forest of our early development and we didn’t have the brains and cognitive tools to stash the event in memory, did it still help shape who we are?

I don’t remember, but I can choose to imagine myself on my siblings’ laps as they read me stories or sang me songs

Bauer says yes. Even if we don’t remember early events, they leave an imprint on the way we understand and feel about ourselves, other people, and the greater world, for better or worse. We have elaborate concepts about birds, dogs, lakes and mountains, for example, even if we can’t recall the experiences that created those concepts. ‘You can’t remember going ice-skating with Uncle Henry, but you understand that skating and visiting relatives are fun,’ Bauer explained. ‘You have a feeling for how nice people are, how reliable they are. You might never be able to pinpoint how you learnt that, but it’s just something you know.’

And we are not the sum of our memories, or at least, not entirely. We are also the story we construct about ourselves, our personal narrative that interprets and assigns meaning to the things we do remember and the things other people tell us about ourselves. Research by the Northwestern University psychologist Dan McAdams, author of The Redemptive Self (2005), suggests that these narratives guide our behaviour and help chart our path into the future. Especially lucky are those of us with redemptive stories, in which we find good fortune even in past adversity.

So our stories are not bald facts etched on stone tablets. They are narratives that move and morph, and that’s the underpinning to much of talk therapy. And here is one uplifting aspect of ageing: our stories of self get better. ‘For whatever reason, we tend to accentuate the positive things more as we age,’ McAdams told me. ‘We have a greater willingness or motivation to see the world in brighter terms. We develop a positivity bias regarding our memories.’

I can’t make myself remember my early life with my siblings nearby and my mother before her breakdown, even if I revisit the mountain idyll where the summers of that life unfolded. But I can employ the kinder lens of ageing and the research by these memory scientists to limn a story on those blank pages that is not stained with loss.

I am by nature trusting and optimistic, traits that I’ve sometimes worried are signs of intellectual weakness, but I can choose to interpret them as approaches to the world developed by myriad, if unrecalled, experiences with a loving family in those early years. I don’t remember, but I can choose to imagine myself on my siblings’ laps as they read me stories or sang me songs or showed me the waving arms of a crawdad from that mountain lake. I can imagine myself on their shoulders, fingers twined in their curly Ohlson hair.

I can imagine them patiently feeding me the lines to The Night Before Christmas, over and over, hour after hour, day after day, because someone had to have done it – my mother told me that I could recite the whole poem when I was two years old. Not that they remember doing this, because most of them were teenagers by then and off having the kinds of encounters with people and culture that would define their sense of self for years to come. But I’ll imagine and reconstruct it, both for me and for them. Because our pasts had to have had a lot of that kind of sweetness, given our lucky loving bonds today. We’ve just forgotten the details.