Not exactly the most insane question, but certainly an uncommon one:

"What's the warmest part of the library?"

It's going to be in the 80s outside today, so we may have had the air conditioner on to compensate, but it's definitely not chilly in the library. He asked very nonchalantly and seemed confused at my confusion when I didn't hear him the first time/asked for clarification.

- Circ. Ass.