A childbirth teacher in my local birth circle posted a hilarious story yesterday in which her first-grade daughter, when asked what a contraction (as in "can't" or "won't") was, said, "it is when your belly hurts really bad and you scream and then you have a baby!" I love it.
Our three year old has been learning a lot about birth in preparation for our birth, and some of his renditions of the process are similarly amusing. Right now his version of the whole thing is, "Miss Wendi comes over, and then you get in the bath, and then the baby comes out of your rump, and then we have cake." (I made a birthday cake for the baby and froze it for birth-day. The cake, by the way, is obviously the most impressive part of the story.) I can't wait to hear him telling people about the experience! That may definitely raise a few eyebrows.