14 Things You Never Knew About St. Patty’s Day

4. The Shamrock

The three leaf clover, or shamrock, is closely associated with the holiday. Everyone knows that a clover with four leaves is considered good luck — because Druid priests believed they helped ward off evil spirits — but why is the three leaf clover so closely associated with the holiday? According to legend, the shamrock was originally intended as a teaching tool. St. Patrick apparently used the ever-present weeds to teach the locals about Catholicism’s Holy Trinity.