I did have a knack for playing weirdos. There's still sort of this perception of me out there as being this crazy guy.

I never told my father I loved him before he died, and I have a lot of issues about that. They're all swimming around in my head, in my heart, unresolved, and in a way it felt fitting to dedicate the film to him.

You choose your friends by their character and your socks by their color.

I did have a knack for playing weirdos. There's still sort of this perception of me out there as being this crazy guy.

And costume is so important for an actor. It absolutely helps to get into character; it's the closest thing to you, it touches you. Some actors like to go into make-up and then put their clothes on, but I like to dress first; that's my routine.

And of course I've got kids of my own now, and they love me being in the Harry Potter films. I'm now part of a phenomenon. You become incredibly cool to your kids, and you get a young fan base. So you became the cool dad at school. You're suddenly hip.

Interesting things come your way but as you get older, your lifestyle changes. I don't want to travel; I don't want to be in a hotel room away from my family.