Counting sheep helps put you to sleep. Treat a burn with butter. Drafts cause colds. Fish is brain food. Reading in bed can ruin your eyes. Simon examines 21 such beliefs, mostly about health and many about food, and labels each one sense or nonsense, with a one-page explanation of why it's valid or isn't. Thus he explains that though any other animal will do, the boring activity of counting sheep jumping over a fence can help you go to sleep. What's more, it occupies both sides of your brain: fixing on the sheep keeps out other, possibly disturbing images, and the process of counting keeps your left brain from concentrating on other problems. The book is too spotty for a systematic lesson on much of anything, but Simon's down-to-earth judgments always make sense, and lots of little professors will be happy to pass on the word.