[This joke is just plain stupid. Actually, I'm embarrassed to run it, but I don't have a decent one to put in its place. I apologize in advance.]
The hunched back man decides very reluctantly, that he should go see a doctor after a few too many people have started to comment on his back.
DOCTOR: I need for you to get undressed, sir. (Hunchback removes jacket and then stops)
HUNCHBACK: I really don't like getting undressed, doctor.
DOCTOR: If you want me to examine your back you'll have to get undressed. (Hunchback removes his shirt but leaves his t-shirt on)
HUNCHBACK: I don't like showing people my back. They always laugh at me.
DOCTOR: Do you want me to examine your back or not? (Very reluctantly, the hunchback removes his t-shirt)
DOCTOR: Ah...just how long is it since you were in school?
HUNCHBACK: Gosh, over 20 years, doctor. Why?
DOCTOR: Did you ever wonder all those years what happened to your backpack?