When it's done it's done...or is it?

Are we as writers ever satisfied with our stories?

While waiting to hear from an agent who requested the entire manuscript, I'm contemplating adding to my already completed novel. Is it the wait that's triggered this insanity or unwillingness to let go of the daily hours and hours spent with my friends, the characters?

I know the next step will involve hours of editing even though I'd like to think that I'm that rare writer who writes the perfect piece, so why add more to it? What's compeling me to do this? Is it intuition or just a whim? I can ask myself the compeling questions about how it would enhance the story or is it necessary, but the question remains, do I leave it alone or start messing with it again?

I keep hoping that the agent will call saying "welcome to my client list." And then the question will be out of my hands.