The first semester of my junior year I was an exchange cadet at the Air Force Academy in Colorado Springs. There were 6 of us from West Point, 6 from Navy, 3 from Coast Guard, and (I think) 6 from the French Air Force Academy who were exchange cadets in the fall of 1985. I had applied to Air Force while a senior in high school but had never received an official letter of declination, so I viewed my goal as an exchange cadet to "see what I missed and show them what they missed."
One of my courses that semester was electrical engineering, taught by Major Phelps. "Phelpsie", as he was sarcastically-affectionately known (like calling a huge guy 'Tiny'), was an extremely competent instructor. He wasn't so personable, but he was a good man. Going in his favor was the fact that he seemed--well, if not biasedtoward, then he at least enjoyed having in his class two West Point exchange cadets.
Major Phelps was tough. He taught a rigorous subject to rigorous standards. His tests could be brutal.
There weren't more than 15 or so of us in the class, and after several attempts at whining and persuasion we won a huge concession from Phelpsie--on the next test, he'd allow us to use a "cheat sheet", a note card with whatever we wanted written on it. We were limited in size to one 5"x8" notecard. This was big--no memorizing formulas this time!
The night before the test I was going through the chapter, making my notecard. I subscribed to the views of the ancient Chinese philosopher Sun-Tzu: know your enemy, and know yourself. Rather than just copying formulas I actually was copying example problems from the book--complete with the explanations for each step. No way would Phelpsie be able to slip one by me now!
I came across one example problem in particular. It was similar to others we had done, but there was a curve ball in it. Phelpsie had mentioned it briefly in class when we had covered that section but that was it. We'd had no homework problems like it, no quiz problems. I knew my enemy, I knew Major Phelps would take that problem and just change the numbers. I copied the example word for word.
After the tests were handed out, you could tell when everyone got to whatever problem it was. There were audible moans. No one could figure out how to do it. No one, that is, except for the one person in class clever and/or lucky enough to have copied a certain example problem from the chapter. You see, Phelpsie didn't even change the numbers :-)
I got the high score in the class on that test--90%. The next highest score was 70%. They went downhill from there. By the next class period Major Phelps had already heard through the grapevine that I had that exact problem on my notecard, and he seemed rather to enjoy letting me know that he knew. He also seemed to enjoy holding it over the heads of the other cadets--If you want to use a notecard, you need to be prepared for harder tests....
Why do I tell this story now? Because during my 6th period trig final today I was wandering the class, offering reassurance to students and answering questions. One girl said with glee, "I have this exact problem on my notecard!" I wonder if she had the other one, too. You see, I lifted two example problems from the text for use on the final exam.
Know your enemy :-)