The best thing I've learned is, if you're going out, never go out alone - you leave yourself vulnerable. If you've got someone else there you trust, they can say, be wary of that person. I probably used to be too trusting of people.

I used to joke I was a point-and-click actor. My whole process has been about trusting your instincts and hitting your mark.

Fans are really important for me. And if they take pains to write me, it's the minimum that I answer myself.

If I can make a career for myself after Harry Potter, and it goes well, and is varied and with longevity, then that puts to bed the 'child actors argument'.

I thought I was an actor playing a wizard. But really, I was a wizard playing an actor.

I think I'm always very naïve. With 'Kill Your Darlings' and 'Horns', I'm like, "Why wouldn't everybody love this?" But I guess it's going to divide people in some ways. But if you're willing to go with it and suspend your disbelief, you're going to get something amazing and something unlike anything else.

If you're having a bad day, get on with your job, because you having a bad day can affect everyone around you.