One year, my wife was teasing me that she had found the perfect gift for me, but wouldn't tell me. I guessed that it was a wool overcoat that I'd been eyeing. She then began to pester me what I was going to get her. So I told her, "A lump of coal"
Well that Christmas, I got this really small box from my wife. Inside was a lump of charcoal! 
She had told her brother the story and he got the charcoal gift for her. Naturally, she later gave me the real gift, the overcoat.
