This article of about 5000 words describes ten widespread ideas that I find ridiculous. They include the certainty that the world was about to end, the virgin birth, the validity of astrology, and the notion that the Americans never went to the moon. It offers my arguments as to why each of these ideas is invalid and, in some cases, suggest explanations for why people continue to believe them. If you are a believer in any of them, I hope you will not be offended and even that I might cause you to reconsider your position. But you be the judge.