Art doesn't just happen by accident. It is about pulling out new tricks and trying new things.
The director is a bit analogous to the conductor of a symphony orchestra. It's a collaborative adventure.
A screenplay is not a finished product; a novel is. A screenplay is a blueprint for something - for a building that will most likely never be built.
Schools and libraries are the twin cornerstones of a civilized society. Libraries are only good if people use them, like books only exist when someone reads them.
I was always a filmmaker before I was anything else. If I was always anything, I was a storyteller, and it never really made much of a difference to me what medium I worked in.
As a writer, you have control of the words you put on the page. But once that manuscript leaves your hand, you give control to the reader. As a director, you are limited by everything: weather, budget, and egos.