The bulletin board ad said, "Human Size Teddy Bear for Sale. Paid $100, asking $50." Next to those words was a color photo of just the teddy bear. It looked new and lovable. But, he wondered, how big is this bear? How big is "human size"? Humans come in all sizes, from infants to sumo wrestlers. Then again, he thought, what does size matter anyhow? It's half price! Valentine's Day was coming up. It'd make a nice gift for his girlfriend. She liked teddy bears. He called her up. He told her about the bear. She asked, "Are you going to buy it for your niece?" He said, "Actually, I was thinking it'd make a sweet Valentine's Day gift for you. You like teddy bears." She said, "You're thinking of giving me a used teddy bear for Valentine's Day?! Go ahead, and I'll get you something even sweeter—used chocolate!"