Adam was walking around the Garden of Eden feeling very lonely, so God asked him, "What's wrong, Adam?"
Adam said he didn't have anyone to talk to.
God thought for a minute and then said that He was going to make Adam a companion and that it would be called a "woman." He said, "This person will gather food for you, cook for you, and when you discover clothing, she'll wash it for you. She will always agree with every decision you make. She will bear your children and never ask you to get up in the middle of the night to take care of them. She will not nag you, and will always be the first to admit she was wrong when you've had a disagreement. She will never have a headache, and will freely give you love and passion whenever you need it."
Adam asked God, "What will a woman like this cost?"
God replied, "An arm and a leg."
Then Adam asked God, "What can I get for a rib?"
And the rest is history.