The Boss's chalk cross
During a summer job as a student back in the mid-1970s the Chief Engineer explained to me the difference among the Layman, the Technician and the Engineer. When his TV goes wrong (all valves in those days, remember), the Layman knew it could probably be fixed by giving it a hefty clout. The Technician knew exactly where to administer that clout. But only the Engineer knew how hard a clout was required.
This rule has resolved many a problem ever since.
Biting the hand that feeds IT
