The novice, in his frustration, struck the side of his computer. The master walked over and asked what he was doing. The novice exclaimed, "my computer is not working and I do not know why!" The master admonished him, saying "you cannot solve the problem by striking the computer without knowing what is wrong." Then the master struck the side of the computer, and it worked flawlessly.
(I love this one because one time I was doing a gig and my computer refused to boot. Suspecting that the vibration from being lugged into the car and taken for a long drive had unseated something slightly, I gave it a sharp smack and power cycled it, and it started up fine.)