Overstudied
The phenomenon in which a person studies for so long that they end up confusing themselves and mixing up information when they go to take a test.
I spent 5 hours studying for my history essay test last week so that I couldn't fail. When I went to take the test, I mixed up all of my topics and essentially lied to my teacher about the Spanish-American war. After telling myself that I overstudied, I also realized that I made up a new word. I am a master of making stuff up. Overstudied.