There's no point in making something if you're not falling in love with the people you're filming and you want them to really enjoy you being around. It would be weird if, when you're making a film, you don't think it's going to be the best ever or the worst ever - I guess it goes from one feeling to another.

I don't make 'issue' films. I like making films about rebels or pioneers or people that are doing something.

People want black and white answers, but it's not one thing or another. I think the only way we're going to make good things is to inspire people and make them feel as though what they're watching is real.

Personally, I don't like watching films about victims - people where you're meant to think, 'Oh, this is terrible,' and you go home feeling really depressed.

I watch mainly fiction. The films I like watching are films where you see people change, like with Boyhood. You see a moment in someone's life where it's a breakthrough. For me, the breakthrough in Boyhood is that amazing moment right at the end when he finds somebody he can feel relaxed with, and who will maybe be a friend for the rest of his life. I like that it doesn't end in a love affair or marriage. It just ends in, "Wow, I found people I can relate to for the first people in my life. These people accept me, I like them."

I don't have any advice at all. I think we all make the films that reflect the kind of people we are; we all make such different films. There's not just one way of doing it.

The magic of documentary is that I keep being surprised and amazed by the things I film.