'm a lightweight; always have been. I didn't get properly drunk until I was 25, on a night out which culminated in a spectacular public vomiting in a Chinese restaurant. Ever wondered what the clatter of 60 pairs of chopsticks being simultaneously dropped in disgust might sound like? Don't ask me. I can't remember. I was too busy bitterly coughing what remained of my guts all over the carpet.

Not a big drinker, then. Like virtually every other member of my generation, I smoked dope throughout my early 20s. It prevented me from getting bored, but also prevented me from achieving much. When you're content to blow an entire fortnight basking on your sofa like a woozy sea lion, playing Super Bomberman, eating Minstrels and sniggering at Alastair Stewart's bombastic voiceover on Police Camera Action! there's not much impetus to push yourself. Marijuana detaches you from the world, like a big pause button. The moment I stopped smoking it I started actually getting stuff done. I still sit on my sofa playing videogames, necking sweets and laughing at the telly, but these days if I have to leave my cocoon and pop to the corner shop to buy a pint of milk before they close, it's a minor inconvenience rather than a protracted mission to Mars. That was the worst thing about being stoned: there came an inevitable point every evening where you'd find yourself shuffling around a massively overlit local convenience store feeling alien and jittery. Brrr. No thanks.