To Manhattanites, New York City usually means Manhattan. This, despite the fact that the city includes five boroughs. So for Manhattanites who've dismissed the four other boroughs in their thoughts and sometimes I have to count myself among them - New York City is a small town.

After you've lived on the island for a while and, in particular, have regularly walked its narrow and wide thoroughfares, you get to know it very well. I certainly have. And as months and years go by, street after street, avenue after avenue come to acquire special meanings. There are events associated with them. There are buildings where you've worked, houses where you've visited friends and family, apartments where you've begun and ended romances.

The locations that come to have the deepest sentimental value are, of course, those where you've lived. (This would be true of any city or town, wouldn't it?) These are streets you've walked again and again, buildings you've entered and exited innumerable times, room in which you've eaten and slept and watched television and dealt with the monthly bills and brushed your teeth and thrown parties. Also, not to put too fine a point on it, matured and aged.

Since I moved to Manhattan almost four decades ago, I've lived in six different apartments on six different streets. When I lived on them I came to know them well without necessarily being aware of how regularly I sensed a change if someone painted a room I could see from outside or installed a new intercom in a doorway. I got used to seeing neighbors whom I never met stroll by me with their dogs. I recognized the sounds and smells without giving it a second thought.

Ane then I've moved away. And every time I have, it's turned out that once transplanted, I haven't have reasons to walk by my former addresses with any regularity. In other words, the streets which I traveled sometimes a dozen or more times daily, I simply left behind. In some cases, as much as a year or two goes by without my getting the chance to visit past haunts.

And over the years I've noticed that when I do retrace old steps, I'm tempted to remember what I felt like when I lived there. I make the effort to recall who I was then, what I was thinking about. But thoughts and feelings are evanescent. They require Proustian efforts to retrieve. People and events, on the other hand, tend to be more concrete.

So what I've come to realize is that although I have the devil's own time remembering who I was then and what I was thinking, I can remember certain particulars neighbors' faces and names, the way light fell through at certain times of the day, where pictures hung and the size of closets.

This was on my mind last week when, walking crosstown and decided to walk along one of my old beats. For eight years in the 60s and 70s I lived on East 63rd Street between Fifth and Madison Avenues. I have always thought of the place as a shabby building on a swanky block. By which I meant that 11 East 63rd Street had been allowed by the landlord to fall into minor disrepair while some of the surrounding buildings were beautifully maintained.

I haven't seen the old digs for some time, I was thinking to myself as I rounded the corner. I wonder what I'll see when I gaze up at the third floor bay window, where for eight years I routinely looked out. Or listened out for the hansom cabs that sometimes drove by or for the man who carted a wheel around on which he sharpened knives. I was wondering if either Mr or Mrs Vas Dias would be peeking out from behind their second-floor shade, as they always did, keeping tabs on who was coming and going.

That was when I got the shock. Neither of the Vas Diases was spying on me from the second floor. There was no way they could. Because get this! the building was no longer there. What had been 11 East 63rd Street no longer existed. Instead, a three-sided wooden wall shielded from pedestrians what was now a construction site. The building were I had lived and which had such burnished meaning for me had been razed so that something of no meaning for me could be erected. The bricks-and-mortar repository of my countless memories was no more.

Yes, I know that cities are constantly changing. (The whole world knows how New York City has changed in the last six months.) But I also know that somehow we all or maybe just most of us regard cities as permanent. People need a sense of permanence, don't they, in order to get by. So, despite all evidence to the contrary, we ascribe that permanence to cities.

This is the moment to mention that my second Manhattan address, 330 East 57th Street, was torn down at least 20 years ago. Now my third one is also a thing of the rapidly vanishing past. As I stood on East 63rd Street, looking at the metal poles sticking up behind the wooden wall, I suddenly got the grim idea that someone or -ones was rampaging around the city wiping out my past. Sure, it was an irrational thought, but certainly a human one.

Manhattan had just called harsh attention to the irrefutable fact that nothing - certainly not the solid artefacts of one's past - is forever, and I didn't like being reminded.

Also by David Finkle:
Coffee house blues
The zen of jay-walking
Changing places
Darkness at noon
Union Square
Making it real
Wake up chillun
Flying the flag
Pleasantville
An ill wind
The absolute place to be
Small change