Things that make me want to throw up/scream

So there are obviously a lot of things that make me want to throw up/scream including mayonnaise but that really isn't the subject of this post. I just have a question for you all... what is that point of a test that you study for, take and think you at least passed and then it turns out you didn't do well (not Brian didn't do well, actual didn't do well). So the professor is difficult to understand and the book was written by him, so it is basically $80 down the toilet, and we dont have a TA (not that it would help, his last TA was too condescending to actually show up for office hours). Why write a test with questions so vague the students dont understand well enough to choose the correct equation. In fact why ask them to solve the equations anyway since you never cover them in class, and the book glosses over 80% of the steps needed to actually solve the equations. It isnt intuitive (if you have this class you have heard that expression before) so I am a little bit confused about how I am going to understand this material... well actually I dont care about understanding at this point, I care about getting a decent grade on the final and getting a solid B in the class... so if any of you understand epidemiology, I mean really truly understand lets chat... we can become best friends because I need at least a B in this class or my dreams of a DrPH are going out the window.