Chatting with a bunch of people about our times in college brought up something that had crossed my mind a few times. Was there a course or subject area in which you could pass or get through, or even got good grades in it, but you thought that you didn't actually had a good grasp on it?
I certainly did. And the subject area was Thermodynamics. For some odd reason, even though I got good grades in it, I just didn't think I actually GET IT when I was an undergraduate. At that time, I thought that the subject was disjointed, and I see a lot of "starting points", where such-and-such an equation or description goes with such-and-such a problem. I didn't see any underlying uniform idea through the whole thing. Yet, I could still do well in exams.
I didn't get that feeling in other subjects, such as Classical Mechanics, E&M, QM, etc. I'm not saying that I find those easy, or easier, but at least I had a clear "view" of the material and able to figure out where I was at any given time. In Thermo, I had a pieces of the puzzle, and I can work with that puzzle, but I never had a clear idea of the whole picture.
That, of course, changed very quickly in graduate school where I finally had to 'apply' stuff that I learned in Thermo, and finally, many parts of it started to sink in. Now, I think, if I were to retake my undergraduate class in that subject, I can see the bigger picture that applies to that particular problem or area. But I found it rather strange and disconcerting that I didn't have that level of understanding at that time.
I'm guessing that this is not unusual, and that a lot of students, especially in the intro physics courses, are able to get through by simply knowing how to work out a problem, rather than having a profound understanding of what they are dealing with.