What do Tests Prove?

I just took my third business test. This is the first one I didn't get an A on - I got a B. The test was over 3 chapters. management and Leadership, Structuring Organizations for Today's Challenges, and Production and operations Management. My Business book came with an online version that is to pace you and make sure you read whats important. You also answer questions relating to the chapters and it molds the learning to your needed areas. On the two previous tests, I had no problem. I read the chapters, did the review, and did it all over again. It seemed to be working. Well, not on this test! I could not for the life of me keep everything straight. Who knew there were 5 different production plans, or that under each one is a set of specific rules to follow! I have been reading these chapters for over a week and a half now. I still am getting answers wrong. So I figured I'd read some more and redo the review. Still did not help that much! So this leads me to my question; what is the point of testing? What does this test prove? That I am not management material? That I'm destined to be a lowly staffer all my life? Does it really prove anything other than I cant memorize all of what someone things I should know before a deadline? I mean, I understand this stuff is important, but would it not be more important if I could put it to practice and see how it effects my understanding of these terms? This is like Isaac Asimov's personal narrative "What is Intelligence, Anyway?" and Russell Baker's personal narrative on "School vs. Education." Its all just stuff that people who are deemed smart in the area of Business management put into a book and say "you need to know this to be like us." No, I don't need to know all this "stuff." Yes, it will help, but until l can put these words to action, then they aren't worth much more than the paper they are written on. According to OTC, that paper is worth a few thousand dollars... Guess I better memorize ever cents' worth...