It's true. You're only really taught to pass an exam - you're not taught about the subject itself. As one of our guidance teachers rightly said, most exams test your knowledge of the English language - even in Chemistry exams, ridiculously simple questions are made out to be so much more difficult due to the awkward wording.
Voila, that makes me Person A! ... -Googles- Ah, that's right. An island in South Asia. 
I mean, she gets pretty good grades in school (A's and B's), so academically, she succeeds. And my brother who's 12...he doesn't really get good grades but is definitely smart when it comes to using his thinking process and knows quite a few facts. It just depends on the individual and their strengths in certain subjects.