Once upon a time, in a certain town there was a coffin maker who opened and was running a store where he sold the coffins he made himself to the customers in the neighborhood. The popuplation in the town increased day-by-day.
A novice was trying to fix a broken Lisp machine by turning the power off and on. Knight, seeing what the student was doing spoke sternly: "You can not fix a machine by just power-cycling it with no understanding of what is going wrong." Knight turned the machine off and on. The machine worked.