Guy: I'm looking for a book, but you probably wouldn't have it...
Me: (wondering if it's something really weird) Well, what book is it?
Guy: Plato's Republic. I'm sure you don't have it.
Me: I think we probably do. Let's see. Oh yes! We have 3 different versions in fact.
Guy: Really?!?! You would have a book like that here?
Me: You just never know what you might find at a library.