Does editing ever end?

I told a friend of mine I was done with my book because I had just changed an "a" to "the." And I was quite sure that made the book better. She told me of something Oscar Wilde supposedly said when asked how his writing was going: "This morning I took out a comma and this afternoon I put it back."

Sounds about right. As it turned out, I was not done editing. The brain keeps remodeling and cutting long after you have put down the blueprint and the knife.