George Lucas said that "you make a movie, given the circumstances". I really like that idea because it makes it immediately clear that your ideal of what you want to do, create, etc. Will change because of the chaos and unpredictability around you.
This is funny because he is the most infamous movie maker for changing movies over and over and over and over and over again (Star Wars). He took "given the circumstances" very liberally. Or another reading that "you make a movie" which never ever ends.
George Lucas may be an idiosyncratic film maker but he is a rather thoughtful person when it comes to making films and I find interviews where he discusses the process to be very interesting.
