Fastest Readers Ever

Okay, so you're probably not smart enough to get this, but listen up. The joke uses a 'double-entendre' with the word 'stories'. When someone asks who the fastest readers are, you expect an answer about reading books really fast. But here, 'stories' refers to the floors of the building where the 9/11 victims fell from. The punchline twists the idea of speed-reading into the extremely fast descent of people during the attack. It's dark humor about a real tragedy, you big dummy.