God said, "Well I've got this thing called a woman. She'll cook your food, clean out your cave, make your bed, get you a drink whenever you want and you can have a thing called sex whenever you need to - but, it will cost you an arm and a leg."
"What would I get for a rib?" asked Adam.
If you were not brought up to be familiar with the Bible, or are not familiar with how Eve was created:
http://en.wikipedia.org/wiki/Eve