Revision Hang-ups

I did a lot of revision on my WIP yesterday in prep for new writing today (did 2 pages of new writing yesterday too, but today is the big push.) Why so much revision before the new words, you ask? Let me tell you: I'm not a forward thinker until the past makes sense.

I can't suddenly change a character's motivation and write it that way from page 134 on knowing that from pages 1 to 133, he's thinking something completely different. I have to change it from the beginning. It's just me. It's just how I work. I know a lot of writers that don't worry about that kind of stuff until the final polish, but I worry that I'd get lost.

As a result, every time I change something or add a layer of detail, I have to go back through the manuscript and make the whole thing work. Not saying I do it with a fine tooth comb, but I hit the big spots, realign what I can. Does this cost me time? Yes. Does it preserve my writing sanity? Yes. And I get happier about the book with every subtle new thing that gets done.

That's my revision hang-up. What's yours?