I know who I am, I know what I can and can't do. I know what I will and won't do. I know what I'm capable of and I don't agree to do things that I don't think I can pull off.
If you want to make a movie, there may be many forces trying to pull you down, but really, a lot of it is will power. You can will it into being if you just believe that you are going to make a movie.