Excellent in all its departments for all these years (founded in 1925 to be a sophisticated humour magazine), it is especially admirable in these Covid-wretched times. The phenomenon of that great city's usually mingling millions being so much locked-down has found the city's best thinkers and writers, the magazine's contributors, stimulated by the unhappy novelty of their plight.

And so my mind's pulse broke into its anticipatory foxtrot when in this week's New Yorker I alighted upon Clare Sestanovich's piece The Joy of Crossing Paths With Strangers.

We are used to the sometimes helpful notion of Stranger Danger but Sestanovich's theme is the life-impoverishing unhappiness of the kind of stranger deprivation wrought by the pandemic. She is on to something.

It can happen anywhere, "in the milk-and-juice aisle [of the supermarket] ... across the subway platform ... that every stranger can, for a split second, become the only person in the world", she muses.

"This has always been my favourite thing about New York. There is no reason to run into anyone here - there are more than eight million of us - but somehow it happens all the time. This past year, our lives receded from the places where these kinds of encounters happen. The subways emptied out. The coffee shop announced that 'lingering' was not allowed. 'Running into someone' would have broken all the rules.

"As the pandemic winds down here, there are many plans to make ... Still, it's the unplanned that I miss most - and that I am desperate to get back.

"There's a Robert Frost poem, called Meeting and Passing,which captures something about why these glancing moments endure. The poem describes two people walking toward each other. They stop and speak. There is nothing especially momentous about it.

"This is not a poem about the wonders of connection - that thing we've all been missing, and are hoping is right around the corner. [Instead] here are two people who meet, but do not merge. We don't know why. But it is by not merging, by simply passing, that they see things anew:

Afterward I went past what you had passed

Before we met, and you what I had passed.

"This is obvious, and almost unnecessary to describe," Sestanovich thinks.

"And yet it's remarkable, too - a cartography of a shared world that does not insist on bringing everyone together. In parting ways, we are still imparting something of ourselves: go ahead; go look; go see what I have seen."

Yes, poetical Clare and Robert are on to something. All of us have these experiences of fleetingly meeting someone (perhaps on a flight, together in a queue, a personable minority-party election candidate at the shops handing us a flier) and of thinking how but for the vagaries of time and place and circumstance us strangers might have been important to one another.

I remember once urgently flying from Australia to the UK to attend a crucial funeral, with my companion in the next seat an Englishwoman hurrying home with family grief duties of her own awaiting her. We said very little to one another (quiet, sincere empathy was all that was called for) and yet in a companionate, asexual way I expect to (sort of) love her till I die.

This kind of poignancy derives in part from the way in which the innocent perfection of these brief relationships is never spoiled. In sustained, gruelling relationships the other's warts (his bad habits! her atrocious political beliefs!) are damagingly revealed to us. By contrast perfect strangers, fleetingly met, have a kind of perfection about them. There is almost no such thing as an imperfect stranger.

One has been meeting so few strangers during these locked-up times that I felt very grateful for my fleeting meeting (so very like the chance encounter described in Frost's poem) with the stranger GP who at an unfamiliar clinic has just vaccinated me against Covid. For our fleeting minutes together she became for me the only person in the world.