1. Celebration of spring fertility (spring is only really happening around the same latitude as Southern Italy, where this holiday was technically invented, but whatever) as celebrated by the Romans. Later overlapped with the feast of St. Valentine, and was accordingly Christianized in a way that made little to no sense (assuming that St. Valentine was not the patron Saint of getting it on).
2. Some damn Hallmark holiday that was designed to make men, no matter what their situation (dating, married, single, playa, whatever) miserable.
1. Let's all celebrate the emerging sexual urges of animals in church. Thank you Valentine's Day!
2. Single men are depressed, dating men are stressed, and married men are teetering on the brink of suicide. Yup, its Valentine's Day.