Some movies are made from the thing you want to do.

It has some characters or subject. Then they take a lot of different scenes and they call that a book or a movie. It is not really a subject with a beginning a middle and an end.

Tarantini make movies like that. Inglorious bastards and pulp fiction. Sergio leoni when he made once upon a time in America.
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When I was trying to write a book I had too much shit in the book. I had no idea how to end it. Scope means write about an area of the subject you want to write about it not the entire subject.