you mean you did the equivalent of me getting Hobbes and Rousseau mixed up ?
lol
or Ricardo and Adam Smith ?
if so i know that feeling - although the one i had a doctor's note for, had been sick beforehand, hand shaking for first 1 hour, and left after 2 (of 3) hours was the exam i did best in
exam after w-ton however with 1:30 sleep and 1 hours revision....