A doctor requested his 85-year-old man patient supply sperm as part of his physical exam. He gave the patient a jar and said, “Take this jar home and bring back a semen sample tomorrow.”

The next day the 85-year-old man reappeared at the doctor’s office and gave him the jar, which was as clean and empty as on the previous day.

The doctor asked, what happened and the man explained.

“Well, doc, it’s like this–first I tried with my right hand, but nothing. Then I tried with my left hand, but still...