But I really think that I never learned those concepts in the first place. All I learned were rules to solve the problems given to me. For example I actually did remember the "chain rule". But those rules had no meaning to me, just moving numbers around. Which means I would never be able apply it to anything. For example, calculus clearly has applications all across basic physics. But I never really made that connection. All this makes me think that exams are much, MUCH less effective at measuring comprehension than we think.