That reminds me of a story a friend's wife told about when she was a substitute teacher. She was about 6 months along with their 2nd child when she had to teach for a 3rd grade teacher who was out having a baby. One of the little boys ask her how long until she had her baby. She explained she was 6 months into it, and had 3 months to go. He told her that she was wrong, that people only carried babies 6 months. They went back and forth about five minutes on this subject, each one trying to convince the other of the rightness of their argument, when he said, "you're right. I was thinking of dogs."