I've spent a great deal of my life doing independent film, and that is partly because the subject matter interests me and partly because that is the basis of the film industry. That's where the film-makers come from, it's where they start and sometimes its where they should have stayed.

I find it difficult to say, like "which child do you prefer the most", and its a sort of surface choice. I've never known how to quite answer that one adequately.

The truth is rarely true and never simple.

People say you never retire in this [film] business and I say, well, not until they retire you.

In anything really, it's finding the reality. You can't be 'real,' but you can create a reality. And that created reality is what the audience believes in. And that's essential. Because if the audience doesn't believe that, they're never going to trust you. And if they don't trust you, you can't lead them up the mountain.

Snowpiercer has both [optimistic and pessimistic]. It was essentially optimistic. The most pessimistic was my part, because of his knowledge. He knows how it started. The status quo, he knows, has to be maintained, otherwise there is no chance. He knows that this revolution is completely understandable and is also commendable. He also knows the negatives. In the end, that's not a very positive position to be in.

The first film is everything you want to say and how you want to say it. Lots of directors will do that and do it really well, but the second film is not so easy.