(Did you know “A joke a day keeps the doctor away”? Unless he happens to be your fun-Doctor, in which case enhanced empathy with him is the outcome!)
The patient went to his doctor for a checkup, and the doctor wrote out a prescription for him in his usual illegible writing.
The patient put it in his pocket, but he forgot to have it filled.
Every morning for two years, he showed it to the conductor as a railroad pass. Twice, it got him into the movies, once into the baseball park, and once into the symphony. He got a raise at work by showing it as a note from the boss.