Riddle: A thief was in the process of robbing the house of a wealthy widow. As he was rifling through the dresser drawers where her jewelry box was located, he came upon a bunch of diamonds. He knew the diamonds were genuine because he had seen the same type many times before, but he left them untouched in the drawer and continued searching the room. When he heard police sirens approaching, he ran from the home empty-handed, not retrieving the diamonds. Did this thief flunk out of crook college? Why didn't he grab those diamonds when he had the chance?
Answer: The diamonds he spotted in the dresser drawer were a bunch of playing cards with the suit of 13 diamonds facing up where he could see them.