Just do as I say, idiot!

A blacksmith wanted to teach his apprentice the skill of forging a piece of steel into a tool.  He placed the steel into the furnace.  He instructed the young man to get a hammer, while he grabbed a pair of tongs.  



Then he said to the apprentice, "To make sure the timing is just right, you must watch me carefully.  When I nod my head, hit it with your hammer."



When the steel was glowing red and hot, the blacksmith carefully grasped it with his tongs, laid the piece on the anvil.  Then he waited.  At just the right moment, he looked at his apprentice and nodded his head.  



The young man raised his hammer and knocked him on the head.



Moral:  Be careful how you give instructions.  Some people would just do as you say.