From Lawrence Block’s Small Town (p. 196): The main character, a novelist, is talking about the writer’s craft, how a writer manages to construct a story idea and how it sort of miraculously appears at his finger tips.
“Oh, there was pleasure in the work itself. That was where the real satisfaction lay. You imagined something and put words together, and you opened a door in the imagination and walked down an untrodden path, and it led to another door. And you opened that, and went off to see where it led, and day by day and page by page an entire alternate universe manifested itself before you.
Sometimes you struggled, and stared for hours at the empty page that reflected the barren imagination. Sometimes, like Flaubert, you spent the morning inserting a comma and the afternoon taking it out.
Sometimes you were able to write, but the words tasted like ashes in the mouth. You tapped at the keys like a field hand chopping cotton, like a factory worker on the assembly line. Somehow the words got on the page, and afterward they turned out as often as not to be as good as words that sang as you typed them, but they weren’t much fun to write.
And sometimes, sometimes, the book came utterly to life and wrote itself. The words came too quickly for the fingers to keep pace with them. Characters spoke their own perfect dialogue spontaneously, and you were the court stenographer, dutifully recording everything they said. Plots, hopelessly tangled, worked themselves out before your eyes, like the Gordian knot magically untying itself. It was you doing it, of course, or otherwise you wouldn’t walk away from the keyboard exhausted, drained, empty. But it was a part of your consciousness that consciousness knew nothing of, and it was sheer joy when it took over and ran the show for you.”
Isn’t that nice? I experienced all of that when I wrote my five novels, how the characters seemed to take over, how the plot line mysteriously worked itself out, how some days were easier than others.