Totally forgot about this one from 8th grade yesterday...

Single Kidney: How do we know all of this stuff about the moon? It's not like anyone's ever been there!

EDIT: Okay, maybe I remembered this wrong. I talked to SK about it this afternoon and he reminded me that we had been talking about the Moon and different planets and what they were made of and how far away the edge of the universe was---and THAT'S what he was saying no one had been to... So the "about the moon" part in the above quote probably didn't actually happen. Sorry. :-p haha!