Steinbeck has some tips on writing, one of which is:
Write freely and as rapidly as possible and throw the whole thing on paper. Never correct or rewrite until the whole thing is down. Rewrite in process is usually found to be an excuse for not going on. It also interferes with flow and rhythm which can only come from a kind of unconscious association with the material.
I was trying to follow this, but I think I only partially agree with hum. Yes, of often, rewriting is an excuse for not going on, but I re-read and rewrote something the other day, and suddenly got really back into it. I think sometimes, it’s a good thing to do to get you re-engaged with your material.