Hypothetically...

Say you haven't studied at all for a very important exam, such as a final exam.
Would you....
A: Spend as much time as you possibly can and cram in a semester worth of material in your brain and go to the exam sleepy and tired?
Or B: Go to sleep early and go to the exam refreshed and not tired?

By the time I figure out an answer to this, it will be too late. I will have been up most of the night thinking, and therefore will not get much sleep, and since I was thinking about this situation for so long, I would have studied nothing. Life is a vicious circle...