We’ll follow that up with an answer:
It’s simple – to get the best grades we can.
Why do we need the best grades we can get?
To get to the best university or get the best job we can?
Why does that matter?
Because then I’ll have more options in life, more money and that would be a good thing.
That’s how thousands of your fellow students will be approaching their exams. They’ve followed the conventional wisdom about having “a grand plan” and their Mummies and Daddies will, once their child becomes a lawyer or a doctor, be very proud and enjoy telling all their friends how wonderfully well little Johnny has done. And their friends will all nod politely.
But striving after something like an “A” grade, purely for its own sake, just to “get” it, while very achievable, is not much of a motivational tool. Salmon can swim upstream but they probably wouldn’t if there was a more rewarding way of getting to fresh water.