The fairy says “I will give you what you most desire if you do someone else’s job for a day.”
The professor says “I’ll be an elementary school teacher. What can be so hard about teaching a bunch of 6-year-olds how to read?” so he is teleported into a classroom. After a few minutes, all the kids’ screaming gets to his nerves, so he throws all his supplies and gives up.
The C.E.O says “I’ll be a waiter. All you do is carry food back and forth. This’ll be a breeze” so he is teleported to a restaurant. After about an hour, all the annoying customers drive him insane, so he smashes his plates on the ground and gives up.
The janitor says “I’ll be an artist” so he is transported to an art facility. He glues all the classroom supplies and shattered plates to a canvas, then sells it for a billion dollars.
The fairy asks the janitor how he was so clever. The janitor says “I got a masters degree in art.”