How could we possibly appreciate the Mona Lisa if Leonardo had written at the bottom of the canvas: 'The lady is smiling because she is hiding a secret from her lover.' This would shackle the viewer to reality, and I don't want this to happen to 2001.

All work and no play makes Jack a dull boy.

It's crazy how you can get yourself in a mess sometimes and not even be able to think about it with any sense and yet not be able to think about anything else.

I'm a slave to my imagination in terms of making narrative films.

I don't think that writers or painters or filmmakers function because they have something they particularly want to say. They have something that they feel. And they like the art form; they like words, or the smell of paint, or celluloid and photographic images and working with actors. I don't think that any genuine artist has ever been oriented by some didactic point of view, even if he thought he was.

Regret isn't going to get me anywhere. It's like being obsessed with something. It doesn't bring you anywhere.

If you really want to communicate something, even if it’s just an emotion or an attitude, let alone an idea, the least effective and least enjoyable way is directly. It only goes in about an inch. But if you can get people to the point where they have to think a moment what it is you’re getting at, and then discover it, the thrill of discovery goes right through the heart.