It's good to reward yourself after a long day.
John has spent all day studying for an upcoming exam.
John wants to decide what to do when he gets home.
John decides that he wants to unwind with a nice cold beer before bed.
John decides to keep trying to do more review at home instead of unwinding a bit.
John is able to relax and fall asleep, which actually ends up helping his long term memory, making him feel more confident in passing.
His stress levels increase, and he begins to feel increasingly anxious about failing his exam.