A doctor at a mental institution is interviewing patients to see if they are ready to go home.
"Right," he says to one patient "you've been recommended for release, tell me, what would you do when you leave here?"
"Well," says the patient "I used to do engineering, so I could go back to that... I might write a book about my time here, I think it would be interesting... and I've discovered an interest in art while I've been here, so I might do a course."
"Ok," says the doctor "those sound like very good things to do."
"And," says the patient "the best thing is that in my spare time, I can carry on being a teapot!"