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 cannot 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.

― kōan from Hacker Lore. Attributed to Tom Knight, one of the primary developers of the Lisp machine at MIT.