Have you ever heard teachers say that they don't allow cheat sheets on tests because students learn the material better without them? Have you ever studied for

Have you ever heard teachers say that they don't allow cheat sheets on tests because students learn the material better without them? Have you ever studied for a test and REALLY mastered the material, and walked away with the feeling that you know it inside and out? It's actually a great feeeling. Alternatively, have you ever managed to squeak and get a decent grade despite the fact you only partially knew the material but had prepared a good enough cheat sheet? I feel like code completion, fast compilers, and debuggers are one big cheat sheet.