I spent the first half-hour of Friday morning looking up competing dictionary definitions of the word “persistent”. My wife had woken up coughing and we were wondering whether this was the start of it – seven days of hopefully mild fever and quarantine for her, and 14 days inside for me and my daughter. While I was Googling those semantics, though, and adjusting to the realities they did or did not imply, the coughing stopped, and we all hung, waiting to hear what would come next.

This strangest of weeks in the capital, in the country, in the world, has cast us all in that role, every hour.

Social media memes from Spanish balconies; the rolling TV news with its ever-present know-your-enemy virus graphic; texts from friends in various shades of banter or distress; Steve from the Wirral on a radio phone-in; briefings from government ministers and scientists – all offer the newly housebound competing fragments to piece together as we try to understand what life looks like on the outside.

Facebook Twitter Pinterest Masks have become a common sight on streets and public transport

That stay-at-home army has watched the terrifying pictures from Italy on a loop and tried to make sense of the numbers – that morbid Eurovision table of infections and deaths. Then, minute by minute, we have each hazarded a range of appropriate ways to respond: trying to move around cities without touching handrails, occupying imaginary two-metre bubbles in the park, coveting bottles of hand sanitiser, leafleting vulnerable neighbours for shopping orders, lying awake worrying about the rent or mortgage, planning garden projects, sharing lectures in epidemiology and crying over cancelled exams. We spend anxious time telling ourselves health is all that matters, fearing for jobs, setting up Skype accounts, cajoling parents and grandparents to stay indoors, keeping hands away from faces, going through stockpiled food too quickly, scrapping over loo roll, taking our temperatures, trusting official advice and not trusting official advice.

One of the most remarkable lessons of the past seven days is just how quickly the mind can make the unthinkable thinkable. A week ago last Friday, Premier League fixtures and the Six Nations rugby were cancelled and there were still plenty of voices arguing overreaction; sympathies were being extended to Liverpool fans. Since then we have not only quietly accommodated the closure of our schools and universities and offices, our theatres and cinemas and museums and places of worship – but demanded much more closure, much faster.

If marching had been advisable the banners would have read: “Shut everything down now!” Can liberal voices ever have been more vehemently in favour of the imposition of martial law and the end of free assembly as they have been this week?

Last Thursday evening, my Twitter feed had been so full of outrage about people “carrying on as normal”, drinking in pubs, going to shops, that I was moved to drive around the streets near where I live in London – through Camden and Islington and Holloway – to witness this “new Luftwaffe” for myself. At 9.30pm there was hardly a car on the streets, and those that were drove very slowly, as if not to disturb the unfathomable quiet. The pubs and restaurants were just about uniformly empty, lit up like a gallery of Edward Hopper paintings.

Contrarily, then, the next afternoon, shops in my local high street were crowded, with people coughing nervously into their elbows, presumably convincing themselves, like me, that just going up the road for a loaf of bread or to pick up a prescription was obviously fine. We caught each others’ eyes at a safe-ish distance and smiled and shrugged. Normally you feel ashamed to be obsessing about trivial choices, but trivial choices now feel suddenly like the big questions. We have come to the end of the first urgent week of, “What exactly should we be doing?” and there are many more to come.

In this new reality, everything can seem like a portent. We seize on pictures of full trains and we seize on pictures of empty trains. Walking home from the high street with my package of asthma inhalers I was thinking I didn’t yet know anyone directly who had the virus – and then that maybe I knew hundreds, untested.

We occasionally look up from screens to say, “It’s so bloody weird/terrifying” or “What’s going to happen?”

It was the first day of spring blossom; two ambulances passed me on their way down the hill. At home, I opened emails from friends much, much closer to the advancing front line: one in Spain who is in the middle of cancer treatment, self-isolated in a bedroom at home and cheerfully determined to get through Ulysses, cursing the prospect of a €100 fine for stepping out into the sunshine; the other a clinical director of a London hospital who says: “We created an initial isolation ward, which is now full, and just finished another ward today, which will likely be full by the weekend.”

Facebook Twitter Pinterest Shops in Deptford stock up, as a worker heads to Terry’s Discounts with fresh supplies Photograph: Andy Hall/The Observer

Tone becomes an issue. How do you check in with a friend who may or may not have lost their livelihood overnight? Too much gravity and you sound like a horseman of the apocalypse, but matey ironies have begun to sound hollow. I scroll through tweets at random; a stranger writes, “My whole scale of preparedness is off. I’m a catastrophiser anyway, but I can’t gauge where catastrophe is at the moment. Am I being too paranoid? Not paranoid enough? Anxiety is mad at the best of times but now it’s got layers of mad.” I add to the hearts of agreement, and then, next one down, do my bit by offering advice to new-generation workers-at-home.

Having mostly been in that particular self-isolation for 20 years now, I’ve narrowed the rules down to two: spend at least as much time in the day walking and talking as you do looking at a screen, and never work lying down. But of course, as I am writing that, I am realising that the new home-working is not the same as the old. It only really makes sense when you are alone. I was struggling to hit a deadline yesterday while my wife was on another Covid-19-crisis conference call with her office from the sofa and my daughter was playing the piano in the hall. In the absence of cafes, I have been checking out park benches with wifi signals. I am writing this at 5am. Unforeseen consequences are our only growth industry.

In our semi-isolation, between calls in the living room, we occasionally look up from screens to confirm, “It’s so bloody weird/terrifying” or to ask, “What’s going to happen?” or to agree, “We’re the lucky ones with jobs.” We are already in the habit of convening at 5pm to watch the latest prime ministerial update. I have veered between thinking that the pacing of announcements has been well-judged in getting the whole population fully onboard, to terror at the gaps in provision.

Facebook Twitter Pinterest Last drinks in a pub in east London, before they all closed until further notice

After Rishi Sunak’s extraordinary pledges to save the economy on Friday, I called my friend Tony, who owns a pub just off the Strand in London, the Devereux, which has been there since 1677, 12 years after the plague. He had watched the news with his last couple of regulars and confirmed that it all added up. “I’d already agreed to pay my staff for the duration,” he said, “though my accountant said I was mad. But this makes it possible. It’s sad to close of course, but I can see a way beyond it now. We’ll be fine.”

Hearing he was about to close his doors for the summer, I got one of those quick, alarming flashes of what it all might possibly look like in a month or six. How much of the fabric of life can you take away before things start to fall apart?

In the once-upon-a-time of last weekend, we’d gone out for breakfast to the local cafe, opening doors with our elbows, looking for an isolated corner table, half-joking that this might be the last meal out of the year. The Portuguese waitress, chatting about what it all might mean, and still hopeful that they could get through, had recommended I read José Saramago’s fable Blindness, in which a whole community is rendered sightless by a plague, apart from one woman, a doctor’s wife, who watches the world go mad around her.

I Kindled it up last night and, as it unfolded in long spooling paragraphs, imagined myself in the role of the woman, and then of the population, before deciding that I’d best leave it for a month or six to find out how it all ended. Instead, I got involved in a Twitter conversation about which pub I’d go to first when the ban was over; I thought about it long and hard. For me, I had to say, the Prince of Wales or the Eagle. It was much too close to call.

• This article was amended on 22 March 2020. A picture caption was corrected to make clear that the man shown with a trolley was delivering stock to a shop.