A 90-year old man went to the doctor's and asked for a sperm count. "It can't be very high, " the doctor said. "There's really no need for it."
But the old man still wanted it all the same. "All right then," the doctor said. She went to her cabinet, got out a small container, and gave it to the man. "Take this jar home, do a little jobby in the jar, and bring it back here."
A week later, the doctor was coming out of her office when she found the old man and his wife sitting in the waiting room. They handed her the jar. "But the jar is empty," she said after looking at it. "I told you that you had to do a little jobby in the jar in order for me to get the sperm count."
"Doc," the man began. "I tried it with my right hand, I tried it with my left hand. My wife tried it with her right hand, and tried it with her left hand. She even tried it with her teeth out. But that damn lid just wouldn't come off!"