The good book

The other day, I asked my wife how she'd like a book she'd recently read. She said, "It got good about halfway through." Which raises an interesting question -- is a book that doesn't get good until midpoint a good book? Do you stick with a book, no matter what? At what point do you give up? In my youth, I finished every book I started (except Under the Volcano, which bested me three different times). I think I was in my mid 20's the first time I decided to put a book aside because I wasn'