When you're playing a real person there's a balance between playing the person in the script and playing the person as he was in life. You have to be respectful and true to who that person was, but at the same time tell the story in the film.

I'm a good person, I hope. But I'm never as good as I want to be, never as nice as I want to be, never as generous as I want to be.

There's a morality... I think there's a moral compass but whether that comes from religion or just from being a good person, and where one starts and the other begins... I'm a good person, I hope. But I'm never as good as I want to be, never as nice as I want to be, never as generous as I want to be.

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.

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

Moths are the ones that freak me out. It's something to do with the way that, if they get squashed, they turn to dust. There's something very wrong about that. It all feels a bit Gothic.

I think if my eight-year-old self could see me at the Royal Albert Hall winning a prize for playing the Doctor on telly, he would need a stiff shot of Irn-Bru.