Writing a screenplay is like making tea, you sprinkle the leaves
into hot water and let the ideas spread and intermingle to create a
blended gestalt. Tea is very delicate and sensitive to contamination by
odours that surround it. Great care must be taken to transport it pure
to destination. The grand complex of a screenplay is similarly open to
contamination.
Shane Carruth, creator of the Indie movie Primer, spent a year
working on the screenplay for Primer. A year spent working out how to
create a profitable venture out of tiny resources.