A man goes into the doctor complaining of terrible headaches. The doctor says "When I have a headache I go home and make love to my wife, then the headache just goes away". The man thanks the doctor and leaves the surgery. A few hours later the doctor gets a phone call from the man saying "Hello Doctor, I did what you said, it's wonderful my headache is completely gone. Oh by the way, your wife would like you to pick up some milk on your way home."