Books about fools?

I need some ideas for April's book club pick. I thought it'd be fun if the theme was "fool," whatever that means to you. Could be a romantic fool, could be a story about someone's folly, could be literal jesters, or anything in between.

Since it's for book club, it'd be best if they're not series, or at least a book that's able to stand on its own if there's sequels.