The stories that I want to tell, especially as a director, don't necessarily have a perfect ending because, the older you get, the more you appreciate a good day versus a happy ending. You understand that life continues on the next day; the reality of things is what happens tomorrow.
I also believe that writing becomes worthwhile and vitalized only through a full and exciting life.
I mean, if you are directing actors to do one thing and then directing them to do something else entirely because the one thing you wanted them to do may not work, then you are just shattering their confidence in the project.