The Value of 'Sitting on a Project'

I've written about 85000 words on my project. I've let it sit for over six months and now I've begun proof-reading it a second time. I've read the first chapter and have changed the story on every page. Unhappy that I've got so many changes to make and that's only chapter one. Twenty-one more chapters to go through. Happy though, that by letting it sit and approaching it with a new eye, so to speak, is helping me discover where I need to add or take away from what I've already written. Wish me luck!