Q: What would we get if we threw all the books in the ocean? A: A title wave!\nWhat do you think is the punchline of the above joke?
Explanation: A tidal wave is produced by the daily tides, which are caused by the gravitational pull of the moon and sun (officially, it is not a tsunami). Books have titles. The words “title wave” sound very much like “tidal wave.” Read all about it!