This I know for sure...

Most writers write multiple drafts of their novels before declaring them ready to submit to an agent or editor. I've been working on edits and revisions of two manuscripts for a while now. After looking over the latest draft of one of them, I still feel like it needs work.

While I realize and accept writing is hard work, there are some days I feel like a lot like Sisyphus must have when the Gods condemned him to spend eternity pushing a rock up a mountain only to have it roll back down when he reached the top.  :o)