These fibs are merely the usual tricks of the pop trade, of course, but Bowie's propensity for self-mythology went further, creating a series of alter-egos which enabled him to make a career out of an identity crisis. 'I think my problem used to be that I was always shy and fairly awkward in social situations,' he says. 'All through my youth, I would use bravado and device - costume and flamboyant behaviour - in a desperate attempt to not be iced out of everything.'

In other words, so you didn't have to be you?

'Exactly.' Bowie stubs out his cigarette, and reaches for another. 'It's interesting how you can do this at parties. In a simple family game such as charades; you see these incredible manifestations of personality come out of Uncle Bill or whoever when he's describing something in mime. That device allows you in an exaggerated form to display who you are. And I used a lot of those things.'

His first public charade, the androgynous and unearthly Ziggy Stardust, was, in a sense, an artist's caricature of a rock star: glittering, outlandish, larger than life. It became a self-fulfilling prophecy. 'Very much so,' he leans forward, warming to the theme. 'And I think I encouraged that. Having created this character, to then want to become him was incredibly tempting. And I was the first volunteer.'

In some strange process of metamorphosis, Ziggy was taken over by the glam-rock icon Aladdin Sane, then the desiccated Thin White Duke, then the 'white soul boy' of Young Americans, until the creator had lost sight of himself in the creations. 'It's OK,' says Bowie, 'as long as you're really in control of the image, as a painter is, for instance. But when you're using yourself as the image it's never quite as simple as that. Because aspects of your own life get mixed into the image that you're trying to project as a character, so it becomes a hybrid of reality and fantasy. And that is an extraordinary situation. Then the awareness that that's not the real you, and you're uncomfortable having to pretend that it is, makes you withdraw. And I withdrew, obviously through the use of drugs, as well, which didn't help at all.'