"You become so obsessed, and that's not a bad thing for a movie. Serve it with that sense that it's the whole world"

This quote by James L. Brooks is a suggestion to filmmakers to be enthusiastic and devoted to their craft. He is suggesting that filmmakers ought to end up being so consumed with their film that it becomes their entire world. This is not a bad thing, as it will help them to create a movie that is of the highest quality. It is essential to be passionate and to put in the effort and devotion that is needed to make an excellent film. By becoming so consumed with the film, filmmakers can guarantee that they are giving it their all which they are producing something that is genuinely unique.