My high school math teacher Mr D was known for one thing. He reused the same exam questions every year. Just changed the numbers. Everyone knew it. He also made a very big deal of collecting every paper back after we reviewed our scores so nobody could pass them to the next year's class. Of course some of my classmates got their hands on a full set of tests from the previous year. Within a week everyone had a copy. Before every exam we'd sit together and work through every problem on the old test until we could solve them in our sleep. When the real exam landed the numbers were different but the logic was identical. We thought we were geniuses. Years later I became a teacher myself. Ran into Mr D at a funeral. Me: I have to confess something. Me: We had a copy of your old tests the whole time. Me: Full set. Every exam. Him: (smirked) Him: Who do you think leaked them? Me: (stared at him) Him: Kids won't study if a teacher tells them to. Him: But if they think they're getting away with something? Him: (shrugged) Him: They study all night. Me: (stood there) Me: (replayed four years of feeling clever) Me: (we were never clever) Me: (he played us perfectly) Me: (I became a teacher and I still got played) Me: (Mr D was built different)