From the Glimmer Train bulletin:

I remember a lecture (Kurt Vonnegut) gave at Smith College where he asked how many people in the full house of two thousand were writing a story at the time. An astonishing number. And how many of you are stuck, he asked. Slightly less, but still remarkable. Add a character, he said.

He was right, but of course it's rarely that simple. . . (E)very story has its artifice as well as its apparition. The hard part is allowing new elements to enter a pre-existing story, and then weaving imagination with structure.