It's always hard when you're playing someone for a lot of people out there who are going to see the movie after reading the books. There's a communion between a reader and the writer, so people will have an idea who Sirius Black is and I might not be everyone's idea of that.

In the past, I’ve had my share of good reviews, but it’s always the crazy, scary, weirdo guy. I don’t even know how it happened. Look at me. I mean, when I’m naked, I look like a bald chicken. How did I get to be a scary bad guy?

So Harry Potter came in and it is nice that I have kids of the right age. I took them to London and they walked around the set and met Harry Potter and that is thrilling.

As a drama student I got into Thirties and Forties suits.

Getting sober was one of the three pivotal events in my life, along with becoming an actor and having a child. Of the three, finding my sobriety was the hardest thing.

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.

I went and lived in Chicago for a year , and I studied at the police academy.