I teach preschool music classes two days a week, and they say some of the funniest things I've ever heard. Seriously. Here's a sampling:
3-year-old: "Smell my armpit. It smells wonderful." (Wait till you hit 12, buddy.)
4-year-old: "I know what kind of new car you should get, Miss Amanda! An S.O.B.!!!"
4-year-old: "Do you smell that?! Do you smell that?!"
4-year old: "Oh. Because I tooted."
3-year-old: "You know what I want for Christmas? A pterodactyl."
Me: "Wow. Why is that?"
3-year-old: "Well. There are a couple of reasons. But the biggest one is that I want him to be as big as the whole world."
Me: "The whole world?"
3-year-old: "Yes. Because then I'd never have to get off of him to get to school. Because. He's as big as the world."
3-year-old: "Something happened at church on Sunday. My mom and dad said it's a secret, and I can't tell you. But it was...wow."
Me: "Um...ok. Maybe you can tell me later."
3-year-old, adopting a 30-year-old expression and tone of voice: "Maybe. But I seriously doubt it."
Me, talking about the reason we celebrate Christmas: "Christmas Day is Jesus' birthday!"
3-year-old, throwing up his hands in exasperation: "Again?! How old is He this time?!"