From a presentation by a security contractor on campus:

1 bottle of beer on the wall, 1 bottle of beer, you take 1 down, pass it around, 0 bottles of beer on the wall.

0 bottles of beer on the wall, 0 bottles of beer, you take 1 down, pass it around, 4294967295 bottles of beer on the wall.

Funny! But it shows analogies between software and the physical world are rarely good!