Because I really care about what I do. I really want it to be right, and I don't quit until I have to. And it's part of the beauty of the experience in life. Nothing can be perfect. Also, perfection is cold.
Imperfection has humanity in it.
Why I love making movies is I'm thrown into nature, into life, into the spontaneity of the moment. If you rely on creative whims rather than facts, you might fail. At least, that is the fear more conservative perfectionists have. Many women may be especially vulnerable to what has been defined as the Impostor Syndrome. One of the tricky aspects of these kinds of thoughts or schemas is that there can be so much validity to them, at least in some situations, at some level.