A noted psychiatrist was a guest at a party. His hostess naturally broached the subject in which the doctor was most at ease. "Would you mind telling me, Doctor", she asked, "how you detect whether or not an individual is mentally challenged who appears to be completely normal?" "Nothing is easier," he replied. "You ask them a simple question which everyone should answer with no trouble. If they hesitate, that puts you on the track." "What sort of question?" "Well, you might ask them, 'Captain Cook made three trips around the world and died during one of them. Which one?'" The woman thought a moment, then said with a nervous laugh, "You wouldn't happen to have another example, would you? I must confess I don't know much about history."