Evan: "Here's a riddle. There are two cars: One is red. One is black. And one is green."
Eric: "You said there were two cars."
Evan: "It's a RIDDLE!"
Evan: "Okay, a bush has five leaves on it. Autumn comes. Three of those leaves fall off. Why are there three left?"
Eric: "I don't know."
Evan: "It grew a new one!"
Eric: "But you said it was fall."
Evan: "Forget the fall part."
Eric: "It's a promising riddle if you forget the fall part. I've got a great idea. This will make it both a riddle and a joke. Say, 'A bush has five leaves on it. Three fall off. Why are there still three leaves on the bush?' Then the person you've said the riddle to will think about it for a long time, and finally he or she will say, 'I don't know. Why?' And you can say, 'Because in the time you spent thinking about it, the bush grew another leaf!'"
Evan: "The problem with that riddle is that the kids at my school don't really appreciate that type of humor."