Whenever I finish a piece of writing, be it a proposal, a short story or a novel I'm always in such a tearing hurry to get my agent's/editor's feedback that almost as I'm writing The End I'm attaching it to send. (There's a poem in there).
The truth is that a cooling off period should be written into every author's schedule. By this I mean letting enough time lapse so a writer can grow sufficiently detached to return to the project and view it objectively.
I've often been delighted with a piece only to return to it after a cooling off period to think, did I really write that?!
Patience is one of the best, and hardest, lessons an author can learn.