After they're experienced, they can do this: A novice was trying to fix a broken Lisp machine by turning the power off and on. Knight, seeing what the student

After they're experienced, they can do this: 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.