There once was a man who went to see a psychiatrist, crippled by a fear of flying. His phobia was based on the belief that there would be a bomb on any plane he boarded. The psychiatrist tried to shift the phobia but couldn't, so he sent his patient to a statistician. The statistician prodded a calculator and informed the man that the odds against there being a bomb on board the next flight he took were half a million to one. The man still wasn't happy, and sat there convinced that he'd be on that one plane out of half a million. So the statistician prodded the calculator again and said 'all right, would you feel safer if the odds were ten million to one against?' The man said, yes, of course he would. So the statistician said 'the odds against there being two, separate, unrelated bombs on board your next flight are exactly ten million to one against.' The man looked puzzled, and said 'that's all well and good, but how does it help me?' The statistician replied: 'It's very simple. You take a bomb on board with you.