I wanted to re-share this because it's such a great story, and also an important lesson for any writer.
You need to be able to move on to the next project and keep writing, no matter how much you've put into a manuscript. Marie Lu's success with Legend is the way bigger example of this, but it also applied to me. Mincemeat is my 5th completed manuscript. The 4th one was rejected by Kristin almost exactly the year before I queried her with Mincemeat.
I would have never gotten to this point if I kept on trying to fix up and polish and resubmit the first novel.