Quote Originally Posted by Mathster View Post
nothing like being around long enough to hear every riddle....
Ouch!

Anyhow, I know the answer is gonna kill a few more of my good brain cells but I can wait!

Here is couple of more goofy possibilities:
The other man was the same guy?
The other guy had already bought a diet coke earlier or he had an empty diet coke can in his hand?
The other guy was wearing a t-shirt that read "Diet Coke for Life"?