I just lost 10 000 words of quite good writing because I realized, while at 30 000 words cumulative, that 10 000 words earlier my character had made a decision (to run off and try to help someone he had met only once, who had decided to ring him at 1am) which he definately would NOT make. I'd love to hear other people's experiences with this kind of thing happening. I think the lesson I've learned is - don't try to twist characters into conforming to a plot, rather forcibly make the plot conform to the characters and what they would really, honestly do. This is a basic lesson I should've learned a long time ago, but I'm glad I lost 10 000 words of good writing in a way. It will reinforce in my mind that I can NEVER ignore my characters, or it will just lead to massive wastes of time and energy when I have to revise huge chunks.