Actually, I am reminded of a story which may or may not be true, but it's a good story nonetheless.
A camp guard at Auschwitz told a Jewish prisoner that he would allow the prisoner to live if the prisoner could tell which one of the guard's eyes was made of glass. The prisoner, without hesitation picked the correct eye which surprised the guard. He asked the prisoner how he could tell which was the glass eye so easily. The prisoner replied that the glass eye was the one that looked human.