<p>But you were still only able to observe a small sample of a huge population.</p>
<p>And that does not always have to do with how hard the courses are. Again, many factors go into it.</p>
<p>You would probably consider me a “slack” person, yet I was able to get A’s in pretty much all my AP classes and passed five exams, most with 4’s or 5’s. I never studied for any of them until the week or so leading up to the exams. I do minimal studying for my DE courses, too, and I get A’s in them except for a B in calculus 2. 
Some people can afford to be “slack.”
It does not mean that the courses in general don’t require as much studying.</p>