My brain is exhausted

I think I did pretty good on the test, despite a couple that I didn't know if I got right or not. For the most part I felt I knew what I was doing. Now for the test tomorrow, all I can say is thank goodness for the one page of notes, or I probably could not make it through. I still do not understand throughput contributions, no matter how many times I read the 2 pages relating to it. I will just have to wing it and thank goodness that a: it is multiple guess, and b: my grade is not on the line!! I already have an A, so even if I bomb it, it won't be detrimental in the long run.. I am off to bed, I deserve some rest and I think my brain is needing a break..