Getting the call to be in The Goblet of Fire was like being welcomed into the most exclusive upper circle of some elite actors' club. You sit on set with the cream of the National Theatre and the RSC, all clutching wands or wearing witches' hats.

If you speak in a different accent, you begin to move in a slightly different way. You think in a slightly different way. It's part of trying to find what makes a character.

I think doing different accents is part of the job of acting, really. It's something else that I quite enjoy the challenge of, to be honest.

How galling to watch someone who looks like you, who basically is you, do all the shagging you didn't get to do.

I've always been a geek and slightly awkward… slightly umm… I was never the cool kid at school.

I often stop when I'm doing something, in the middle of rehearsals or some other job, and I try to take a minute to think "Okay, this might be as good as it gets, so drink it in, appreciate it now". So far, I've been lucky because another job has always come along to equal the last.

I always like seeing people transforming themselves, in whatever way that might be, and a different accent is part of that.