"What is the knob, doctor?" she asked.
"It is a procedure whre we install a knob under your hair on the back of your head. We then connect it to the facial muscles and skin which sag, and when you see new wrinkles and sagging, you just tighten the knob a few turns and your skin is nice and tight again."
"Oh, yes! that is what I would like to have", she replied excitedly.
The operation was a complete success and she looked 15 years younger.
As time passed, when she would notice a new sagging, she would simply tighten the knob and voila! Her face was again beautiful. One day about 8 years later she woke up one morning and saw very larg bags under her eyes. Alarmed, she called doctor and reported the bags.
"You better get right over and let me check this out!" the doctor replied.
After examining her, he said, "The bags under your eyes are your breasts."
"Well", she said. "I guess that explains the goatee."