There's a Reason Pac-Man Smiles.
It's because he knows he's going to wolf down on the meal that is your bottle cap. If you recall, the ghosts from Pac-Man have little tentacle-type fringes, and so do bottle caps, kind of. They're both wavy at the bottom. You know what we're talking about. Now, go turn some bottle caps blue, give Pac-Man a feast, and try not to Ghost at the end of the night.