John Hodge was born in 1964. He won a Bafta and was nominated for an Oscar for his Trainspotting (1996) script. His screenplays include Shallow Grave (1994) and The Beach (2001).

Shallow Grave was my first screenplay, Trainspotting my second. Andrew Macdonald [the producer] gave me Irvine Welsh’s book. It was very good, but it was hard to think how it could be a film. There’s no story, it’s a collection of anecdotes and short stories. The challenge was to make it a narrative without imposing too much structure.

Renton (Ewan McGregor) was the main voice, and I realised he would be the guide. I chose my favourite bits of the book, wrote down in what order they might appear, then that expanded into a script. My advice would be to write a few scenes that you find easy to visualise, really quickly. Keep moving. Don’t get it right, get it down. Don’t labour over scenes or get bogged down.

The first draft took five months, the second six weeks. I went to a few rehearsals but didn’t hang around on set. You have to let the director have control. It wasn’t without its arguments, but Trainspotting worked well because everyone was working in the same direction. Dennis Potter, I think, once said an actor in Gorky Park had been an “oar out of the water”, meaning disruptive – there was none of that.

My favourite scene is the one that has become famous, where Renton disappears down the toilet. I was just looking for an interesting way to finish a scene and Danny [Boyle, the director], Andrew [Macdonald] and I didn’t want to make the stock, pious, po-faced drama about drugs. This wasn’t going to be a preaching film. The humour of the characters was going to be surprising. It generated strong reactions.

Success does bring pressure but it also leads on to the next job. I didn’t do a screenwriting course. I trained and qualified, but never practised as a doctor. To get into screenwriting you need to be lucky and persevering. A good writing course will help you only if you have a talent. Once you’re in, there are a few genius screenwriters, there are a few who are terrible and the rest of us, the 95 per cent, who make the effort to deliver. I’m working on Young Stalin. A biographical subject is new for me.

It’s not a great job if you’re an egotistical artist. Occasionally, I wonder if I should be a doctor and I’ve worked on things that haven’t worked out – The Beach was well done, though it had a lot of people pulling it in different directions – but you do what you’re paid to do.

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