Dr Geezer
An elderly physician, Doctor Geezer, became very bored in retirement and decided to re-open a medical clinic. He put a sign up outside that said: "Dr. Geezer's clinic: Get your treatment for $500 - if not cured, get back $1,000."
Doctor Young, who was positive that this old geezer didn't know beans about medicine, thought this would be a great opportunity to get $1,000. So he went to Dr. Geezer's clinic.
Dr. Young: "Dr. Geezer, I have lost all taste in my mouth. Can you please help me?"
Dr. Geezer: "Nurse, please bring medicine from box 22 and put 3 drops in Dr. Young's mouth."
Dr. Young: “Aaagh! -- This is Gasoline!"
Dr. Geezer: "Congratulations! You've got your taste back. That will be $500.”
Dr. Young, very annoyed, goes back after a couple of days figuring to recover his money.
Dr. Young: "I have lost my memory; I cannot remember anything."
Dr. Geezer: "Nurse, please bring medicine from box 22 and put 3 drops in the patient's mouth."
Dr. Young: "Oh, no you don't -- that's Gasoline!"
Dr. Geezer: "Congratulations! You've got your memory back. That will be $500."
Dr. Young (now having lost $1000) leaves angrily and comes back after several more days.
Dr. Young: "My eyesight has become weak. I can hardly see anything!"
Dr. Geezer: "Well, I don't have any medicine for that, so here's $1000." (giving him a $10 bill)
Dr. Young: "But this is only $10!"
Dr. Geezer: "Congratulations! You’ve got your vision back! That will be $500."
Moral of story -- Just because you're "Young" doesn't mean that you can outsmart an old Geezer.
Remember: Don't make old people mad. We don't like being old in the first place, so it doesn't take much to piss us off.