When you play Pac-Man, you eat small, digital dots and are persecuted by four ghosts - Inky, Blinky, Pinky and Clyde. Why do the ghosts chase you, though? They do not chase one another.
The chase you because you're different to them... You're a Pac-Man - the only Pac-Man. And they are all ghosts, picking on the different one. And that's not all. If you notice the way the game plays, the ghosts do not chase you independantly. They actually gang up on you, and corner you in the maze, like school bullies cornering an unpopular child.
Pac-Man, however, can turn the tables on these evil fascist zombies - he can take a Power Pill and eat them all up. And upon taking the Power Pill, there are two ways one can approach the effects: One can use them as an opportunity to consume dots without being hassled by the ghosts - who become frightened and run away from you - or you can seek revenge, and actually chase them down and eat them, upon which you are awarded a few hundred points, more points for the more ghosts you eat up.
But there's a twist. If you chase the ghosts for too long, the begin to flash. If you continue to chase them, they turn back into ghosts - and if you catch a flashing ghost at just the wrong moment, it destroys you and ends one of your lives. And when you do catch the ghosts, what happens to them? They turn into disembodied eyes which fly back to their base and are reincarnated - as non-frightened, very angry ghosts who go right back to chasing and killing you. The hunted becomes the hunter once more. And your own lust for vengance has only sped up the process, and made things worse. Just like in [insert troubled nation here].
And that's the truth about Pac-Man - it is a moral game which demonstrates the evils of prejudice and the futility of revenge.
And also the evils of drugs. Seriously, Pac-Man, you've got a problem.
EDIT: For an alternative explanation, which even has it's own t-shirt...