[Joker_vD]

Game theory? Imagine a simple game of hunter and prey. There are two locations that they need to chose from. If they both chose the same location, the hunter wins. If they chose differently, the prey wins.

Now, if the hunter can accurately predict the prey's choice, they obviously simply need to select that same choice to always win. The similar logic works for the prey; but this means they can't both be perfect predictors of the future — if the hunter predicts that the prey will choose T, they will choose T as well, but that means the the prey will predict the hunter choosing T and will choose F instead, so the hunter has actually to predict that the prey will choose F, and so they will choose F as well, but that means the the prey will predict the hunter choosing F and will choose T instead...