I've noticed that some of you may be reading these captions before you read the strips. For those of you who do, realize that the captions reveal some details about the cartoon, and so you need to read the strips first.
This came from a dream I once had, except I replaced one detail with another. The original was that only the duplicated objects could tell each other apart; they looked completely identical to everyone else. I replaced that detail with the "having a system" idea. The numbers were originally on the backs of their heads, but then I realized that that would seem a little like tattoos, so I moved the numbers to their shirts.
We'll hopefully be posting a new poll soon.