A professor, teaching a college sexuality class, was discussing the frequency of sex that could still be considered normal. "Many people find that sex every other week is sufficient frequency to satisfy, and that's fine. Yet others want to make love nightly, and there's nothing wrong with that either. Let's take an informal survey of this class. Don't be embarrassed. Please answer honestly. How many people here make love more than twice a week?" A few hands shot up. "Twice a week?" A few more hands. "Weekly, on average?" Many hands. "Once every two weeks?" he continued and, "Once a month?" and "Once every several months?" and finally, "Once a year?" At this last category, one hand shot up, waving most eagerly. "Pardon my curiosity," the professor asked, "But if you only make love once a year, why are you so excited over it?" Replied the student, "Tonight's the night!"