I heard this from Marco who heard it from Tzachi. Not sure what to make of it, but that will not deter me from ruminating publicly

There is a sack of chocolate and you have two options: either take one piece from the sack to yourself, or take three pieces which will be given to Dylan. Dylan also has two options: one pieces for himself or three to you. After you both made your choices independently each goes home with the amount of chocolate he collected.

Write down the payoff matrix for this game and you’ll get the Prisoner’s Dilemma. But where is the dilemma here ? In the few occasions that I presented the Nash solution to the prisoner’s dilemma to a friend who didn’t know about game theory, the response was always `something is wrong here’. I am pretty sure that if I try to do the same with the Chocolate Dilemma the response will be `well, duh’. Obviously every sensible person will prefer one chocolate piece to himself than three pieces to somebody else.

One can say that this hypothetical response vindicates the Nash solution also in the Prisoner’s Dilemma. After all, these are the same games. If people find the solution intuitive in the Chocolate Dilemma they should also accept it in the Prisoner’s Dilemma. But this argument is not very convincing since these are the same games only because we game theorists identify a game with its payoff matrix. The rest of the world might disagree.