There's something called the HSC in Australia...it's basically a system of exams which operates to give you a final rank, which goes up in 0.05 increments and gives you offers into different universities and whatnot. It's not a big deal if you don't give a crap. And after going through it, you'll look back and think, well that was a waste of life. But it is a big deal if you value speed and feeling that release after working consistently for a year.
It's made me realise a lot, of how routine is still underrated in this world and the fact that we are being sorted out by ranks is de-motivating so to speak but at the same time, it's wonderful when you're told you're "smarter" or have "beaten" 95% of the state.
Still, I know how stressed it makes some people feel and although you reading this have no connections with the HSC whatsoever, I'm guessing you've opened this thread because you're feeling just as stressed out. And it's okay. Everyone says to go for a walk, but really you know what works for you. Place your task in perspective. The human brain is an amazing thing - it has the power to store huge amounts of knowledge. There's probably something stuck at the back somewhere from like half a year ago, which WILL come back out when you are forced on the spot to impromptu something or are tested on it. Let your brilliance shine and remember that it is the 21st century and you have the internet.
Cheers, until next time.