One of the things that I find so exciting about life is that you're constantly surprised. You never know what's going to happen, and it's certainly like that making movies; every once in a while, one will come along that transcends all of your expectations.
In life and in movies, it's a similar challenge, where you have expectations, and you end up in situations that are not meeting your expectations.
Sometimes you'll have a movie that you're very proud of and you think it transcended all of your expectations but it doesn't come out at the right time. I have done movies that have never been released. That can be depressing.