As I'm rereading the chapters of Erin's Rebel, I'm sometimes amazed that I actually wrote this thing. I'm going back through the entire novel revising chapters as I go.
After writing the ending of a book, I sometimes forget what I wrote in the earlier chapters. Although I've revised the beginning again and again for contests, the middle chapters I've only seen once. In an earlier revision to expand the book, I actually rewrote a scene in a chapter that I'd already written, but had forgotten about!
Getting a breather from a book you're writing is a good thing. It gives you the perspective of a reader as you're revising. You can look at it with fresh eyes.
And, by the time you reach the end of a novel, you can forget what happened in the beginning.
It's kind of fun rereading something you wrote and thinking, did I write that?