Did you ever write something, and then go back to revise one little part, and end up changing the whole thing?
I can say with complete certainty that’s never happened to me before. Usually when I go back to edit short stories or chapters of a novel, it started out as a grammatical error or the use of an unnecessary word. The only change in the story I’ve gotten from those corrections was a slight improvement. I enjoy reading stories with a tight prose, so I expect the same thing out of myself when I write.