I'm early, I have a purple flower in my hair, I'm travelling fast, and there's singing on the tube. Lone voice wavering operatically.Port a beul, wordless mouth music, no particular key but it's loud and deliberate, not the usual loony tunes or muttered psalms you get, sometimes, on here. The tube is packed but as usual most of the travellers are oblivious, blanked out: only me and a little girl opposite (a pointy-eared pixiechild, bouncing in her seat) seem to be able to hear the voice. We swap grins and strain our necks to see where it's coming from, this trippy singing, but then the train stops at a station, people get on and the singing's joined by a squeezebox, folded in and out by the grubby hands of a teenage gypsy. Weird, weird and weirder, the singing battling this crazy fairground tune, all diminished fifths and spooky minors and just for a second it weirds me out a little too much  - but then the singing stops, and the squeezebox gets off, and so do I. For once at the mainline station my train's in. Six minutes till it leaves, plenty of time so I relax, go grab a smoothie for the journey. Saunter off to platform 1 where the notice board says the train is, sit there waiting for it to leave. It takes a while, and nobody else gets on. That gives me a faint flicker of wrongness, but then it comes to life and chugs off, so I sink happily into the book I am reading. Twenty minutes later I look up and realise: shit, I'm on the wrong train.

Check where it's going, realise that some way down the line there's a place I can bounce off from, back to the line I need, relax again - but the book's abandoned, the windows are far too interesting now. Places I haven't seen since I was a kid. Gran used to live here, years and years ago. Tower blocks flashing past (was that it, there, that one?) remembering the stairs we climbed when the lift was broken, sliding down the banisters every week on the way out, till she got too old to be so high and they shifted her out to the country. Later memories coming in now as we travel. Ten-year-old me, running away, getting on the ferry, not liking the other side (grey dead warehouses with blind eyes, stinking sugar factory, industrial wasteland) and coming back again. Fifteen-year-old me, spiky-headed spraycanned me, hanging out here, getting up to no good. More flashes of memory come thick and fast as the train rattles down the line and it strikes me that since I've been here, I've spent a hell of a lot of hours visiting other people's history, but this is the first time I've encountered my own. Also probably the first time I've been old enough to be amused by it. Thousands upon thousands of miles now between me and the essence of here, and it's a fairground ghost train ride through a host of faces and places. Concrete walkways, smashed bus shelters, deserted stations covered in graffiti in the arse-end of nowhere, and one of those stations is where we got arrested, once, but I can't remember which one. Sudden vivid flash of a face in memory, sharp and clear though I haven't thought of it in years. Fierce violently sweet sixteen-year-old kisses in a smashed bus shelter. Moonlight on concrete walkways, burning cars below us. Twin tags slashed in silver paint, 4 EVER scrawled underneath and it seemed like forever, always does when you're sixteen, but it was maybe two months. I kept his picture, still have it somewhere. Tall thin dark. Shaven head. Diffident smile, raised eyebrow,come on, I dare you. Bad fun and danger boy, but something nice and homely about him: he always took me to see his mum and brothers on a Sunday, though he never met my family, who would not have approved at all. We split because he was arrested, on his own this time. TDA: Taking and Driving Away. He got sent to Borstal, and by the time he came out I was long gone. End of story.

But it's all so clear in my head suddenly as we flash through this industrial wasteland, like those records that get shoved to the back of the collection and forgotten completely until you stumble across them, years later, and think:wow, did I buy this? was that me?And you play each one to the end, searching, listening hard to find whatever it was that made you buy it. I get off the wrong train and change for the right train, full of this happy excited feeling like I've just unearthed a stash of buried treasure. Dig yourself up sometime, see what you find..