You hand a man a deck of cards. He stands in front of the audience and holds them face down behind his back. You tell him to remove any card from within the deck, keep his eyes tightly closed, and while thus incapacitated bring the card around, still with its back to the audience, touch it to his forehead for a second and then put it safely into his back pocket. He can't (and doesn't) know what it is. You can't possibly read his mind because of that. And yet, after he opens his eyes, you tell him to pick…