This teeming, blazing patchwork of rumpus streets and villages I call home

I was a country boy, brought up 20 minutes south of Constable's valley, in a village my father's family have lived in for four generations. We did country things: petting animals if they were domestic, chasing them if they were wild. Books, pictures, classical music were all suspicious - the sort of things that townies liked. Towns were worst of all. The lights of Braintree burned on the horizon like the flames of Sodom and Gomorrah. Seventy miles beyond them was an even more dreadful pit of corruption. London.

As soon as I left home (which was when I left for university), London was where I wanted to be. A decade or so later and I'd made it - drawn not so much, now, by the thrill of otherness, as by the sense of treasure-trove. Amidst London's millions of histories, geographies, mysteries and lives I might discover my own life. The possibilities seemed endless.

I was working in William IV Street, on the northern edge of Trafalgar Square, and living out towards Stamford Brook. My father imagined my daily commute as a journey from one chamber of hell to another. To me it was a rattling ride from suburbs which, though not quite Metroland, at least made me think of Betjeman, to a vortex of ancient authority and fascination.

On my first day at work, I passed Graham Greene in the street, his eyes blue as cornflowers. When I looked out from the front door, I saw St Martin-in-the-Fields. Constable had been married there: London might be another world, but at least I was in the same galaxy. I started trotting round with a Pevsner.

One weekend I'd tackle somewhere famous - the twiddly magnificence of the Houses of Parliament, Westminster Abbey and Poets' Corner, or the wide, shallow, skimming steps leading up and inside the dome of St Paul's. Then next weekend I'd surprise myself with somewhere I'd barely heard of: the leaping tower of St Dunstan-in-the-West, on Fleet Street, or Butterfield's astounding All Saints, Margaret Street, where austerity and magnificence compete.

And if I was fed up with buildings (I was never fed up with buildings), I'd explore parks. And if not parks then Inns of Court. And if not Inns then museums and galleries. And if not museums and galleries then by ways and back-waters. And if not back-waters then the Thames path, taking the Tube out to Richmond, say, and tramping in towards the centre of town for as long as I had the energy to keep going. The point was to learn the lie of the land, and know it as well as I had known the lanes and fields I had left behind.

I have never managed to do that. London is too immense, too unfathomable, too kaleidoscopic. After I'd lived here for a year or two, I learned to accept I would never grasp it whole. Thirty years on, I relish the sense of falling short - which makes me feel I have gradually, finally and unchangeably become a Londoner.

For those born here, the word will mean something that is theirs by right. For the millions like me, who came from one kind of elsewhere or another, it is a differently-conscious kind of pleasure. And however we phrase it, this pleasure always emerges as some kind of paradox, resting on the stories of common humanity that we trace in our stones like geologists reading a rock-face. London is a teeming diversity, unified by the certainty of its own variety. It satisfies our primitive need for cohesion, but also allows us space to be different. It shows itself as a great city, and as a honeycomb of villages. As a blaze of glamorous bright lights, and an echo-chamber of secrets. As a main-street rumpus, and a patchwork of green shades.

It is the place where we know who we are, but are endlessly given the chance to modify the idea of what we might become.

That's why, after any time away, London's Lucozade glow on the skyline is always heart-lifting. It is a proof that we are coming home, and that home is a place of adventure.