It takes courage and It's incomparable. In high school you feel pressure because how well you do will influence the what you will end up studying in uni, which will literally shape your life. Once you're in, you're in, but exams are 3643645times harder, the material for each exam is bigger than the material for all the subjects during one year of high school and all the exams are packed up in the same week.
I feared as much. I'd better enjoy the last 18 months of being in school, then. Things won't be the same afterwards, that's for sure.