"Man oh man, I do not feel prepared for this test."
"What if I fail the test?!"
"What if I then fail the class?!"
"What if I end up failing my Junior year?!"
"WHAT IF I END UP FAILING HIGH SCHOOL?!?!?"
"Then I wouldn't be able to go to college or get a job, right?"
"What if I end up living on the streets D:"
So basically, when I get stressed over a test, my mind wanders to how awful my life will be on the streets. That doesn't really help me out with studying, either.... :(