When your mind goes blank...

So I've been preparing for my nutrition test for a while. I've been studying my notes every night for the past week, so I was feeling confident that I'd do well on the test. When I walked into class today I took out my notes and looked over them one last time before the test. As soon as I began the test, my mind went blank. Everything I had studied and learned just decided to leave my mind all of a sudden. It was as if my brain decided to take a nap right when the tests were being handed out. Although I pretty much forgot everything, I tried the best I could. Hopefully my grade isn't as bad as I think it will be. I'm not sure If I studied too much, if that's possible, or if I didn't study enough. I just hope that my mind doesn't ever go blank before a test again. I'm glad the test is over with at least, and now I can focus on other projects and tests that are due this week!