Happy St. Patrick's Day!

It's green season. By that I mean St. Patrick's Day, not Earth Day; that's on April 20, natch!
You tend to see a lot-and I do mean a lot-of a green even in the beer you drink (Irish beer). And it's all to celebrate the Irish holiday. Wonder who was Patrick? What did he do to be deserve to be called a saint? They must have a huge-I mean HUGE-celebration in Ireland on St. Paddy's Day. Is it really true that there's luck in a four leaf clover and not a three leaf one? If so, will it bring luck to other people who aren't Irish? Questions abound.... Curiosity can kill a cat and I'm a cat.
Note: I love cats even though I can't stand being 'round 'em.