I recently read a Paul Simon interview.  He said:

"A lot of people believe first idea, best idea, but I don't. I'll sing a song many, many times before I get the vocal I want. I re-write songs, not because I'm trying to make them more commercial, but because there's something about them that's unsatisfying to me. My thought is that the ear always goes to the irritant and, eventually, you find the thing you don't like in a song and that's got to go. Sometimes it takes me a year or two. I'll be in denial about it. But once it goes, then I'll try and fix it."

Paul put into words (perfectly) why I am so frustrated with my writing...and why I have taken so long to publish this novel. Each time I reread one of my manuscripts, making edits as I go, I tell myself I've done a great job...it's ready for publication...but, just to be sure, I'll give it one more read. And then, like Paul said, "my ear goes to the irritant" and I find myself changing tons of wrong that seemed so right.