People have an idea that one is in control of a career, a lot more than you really are. You can engineer things to an extent. But you are at the mercy of what comes in across the desk.

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.

One of my career ambitions was fulfilled working with John [Hurt]. I loved his work long before I ever had the idea of being an actor, so I was nervous to meet him. I was like a fanboy, like that annoying character on 'Saturday Night Live'. I'm sitting there. 'Do you remember when you were in 'Midnight Express'? Remember that scene you were in?' And he doesn't disappoint.

It's becoming increasingly harder and harder; there's no such thing as independent film anymore. There aren't any, they don't exist. In the old days you could go and get a certain amount of the budget with foreign sales, now everybody wants a marketable angle.

You take what you know, and you put it through your own prism. If I play characters that break down or cry, it's Gary Oldman crying; it's not the character crying.

I had a guitar when I was 6 or 7, a plastic guitar with the Beatles' faces on it. It would be a collector's item now. It would fetch a hefty sum, I imagine.

The book tells you everything you need to know. The book is the map of the world that you're in with the character.