There comes a point when I'm in the midst of rewriting a novel where I've read the darn thing so many times that the words just turn into a jumble of nonsense. Names and adjectives and he said and they said, it all just runs together, and I can no longer read the thing. Suddenly, it just seems like an absolute mess, and I can't make heads or tails of it.
Not sure that makes any sense, but the point is, there comes a point in rewriting where you just have to walk away for a while, because you have over-saturated your mind with the text. I believe I am at that point with Thorn and Shadow. I've gotten there with all of my novels at some point in the rewriting process. I rewrote Mary of the Aether twelve times, and the high number of revisions was partly the result of not stepping away and getting a fresh perspective.
So there you go. Over-saturation, folks. It can be a killer. Put your manuscript down for a few days or weeks and come back to it with fresh eyes.