I am so used to plunging into the unknown that any other surroundings and form of existence strike me as exotic and unsuitable for human beings. - Werner Herzog

Your film is like your children. You might want a child with certain qualities, but you are never going to get the exact specification right. The film has a privilege to live its own life and develop its own character. To suppress this is dangerous. It is an approach that works the other way too: sometimes the footage has amazing qualities that you did not expect.

Actually, for some time now I have given some thought to opening a film school. But if I did start one up you would only be allowed to fill out an application form after you have walked alone on foot, let's say from Madrid to Kiev, a distance of about five thousand kilometres. While walking, write. Write about your experiences and give me your notebooks. I would be able to tell who had really walked the distance and who had not. While you are walking you would learn much more about filmmaking and what it truly involves than you ever would sitting in a classroom. During your voyage you will learn more about what your future holds than in five years at film school. Your experiences would be the very opposite of academic knowledge, for academia is the death of cinema. It is the very opposite of passion.

Perseverance is where the gods dwell.