You have no authority with your opinion though if you are not qualified. The exam process doesnt give your papers back to check your results against the text books and what the teachers have stated, so using science and previous observations going back at least 12,000years namely the various religions invented over time, people in authority can reinforce their positions by making sure trouble makers fail even as kids.
Unfortunately knowledge alone does not equal access to mechanisms of these disciplines. Without wealth, good luck using your law or medical knowledge to improve your situation aside from preventative measures. However, if knowledge is all you got, it's better than nothing at all and puts you ahead of many who won't be bothered.