This is my absolute favorite joke in the world. It's incredibly stupid, and it's only funny if you tell it to someone. I dare you to say it to somebody and keep a strait face.
Q: What do a duck and a bicycle have in common?
A: They both have wheels..except the duck!
(I've gotten some fairly scary answers to that, too..)
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You know, Hobbes, some days even my lucky rocketship underpants don't help. - Calvin