St. Valentine's Day originated from ancient Roman fertility festivals held in mid-February. Over time, it became associated with expressing romantic love. While the historical St. Valentine is obscure, the modern tradition of exchanging love messages and gifts on February 14th has endured. People of all ages celebrate by sending cards, giving flowers and chocolates, and hosting parties where hearts and cupids are prominent themes. Activities like composing valentines or playing love-themed games are also common ways to mark the lighthearted lovers' holiday.