>If, there have already been 500 people making jokes in the same way as Feynman did -- for instance, if before reading his book, everyone already played prank on some waitress girl in a restaurant by putting the tips under an upside-down filled cup, would they still find the description in the book funny? Just like what I typed, do you still find this re-description of Feynman's joke funny, like the first time you read about it?

I was making the implicit assumption that there is an unbounded quantity of potential jokes. 500 Feynmen wouldn't all be making the same jokes; they'd all make different jokes. Just like how 500 Feynmen wouldn't all be writing the same books or making the same scientific discoveries.