I had a similar experience with a Visual Basic class at community college (required credit for the degree at the time). Since the class was kind of boring (was already a C programmer, Basic was way in my past at that point), I wanted to make the projects more interesting. So, on a calculator project, we were to make a hand-held calculator emulator. I asked if there were any restrictions on the type of calculator, and was told no -- any one. So I emulated an HP RPN style calculator. But since the instructor never heard of RPN before, and despite an introduction screen explaining it, he still failed the assignment.