Mark, went into a convenience store to prepay for gasoline and returned with two plastic bottles of soda. As he filled the tank, his wife opened a bottle. To her dismay it fizzed and foamed all over her lap.

Several miles down the road, Mark asked for his soda. Handing it to him, She warned, "Be careful. These are really over-carbonated." But when Mark opened his bottle, it barely hissed. Eyes on the road, he nonchalantly said, "You must have gotten the one I dropped."