I've been picking up found pennies for years, I think ever since I saw Grease for the first time when I was a teenager. Generally, I don't believe in luck, especially as something that is a necessary result of some random event like finding a penny. But, like clockwork, I pick up every penny I find.

find a penny, pick it up
all day long you'll have good luck

I actually found one this morning in the parking lot outside my office. Autopilot kicked in; I picked it up, recited the rhyme above in my head, shoved it into my pocket, and went into work.

Later in the day I pulled the penny out as I reached for my keys. I suppose I had good luck today, all day long, though it's hard to tell. I did have an idea, though. From now on, starting with this particular penny, I'm going to keep all found pennies together.

Why not.