1. Well rested, well tested, and
2. Study too long, you're wrong.
I might have been on to something 26 years ago:
There are lots of distractions in the modern world that lead people to stay up late in the night. For students, though, there is also homework. On the night before a big exam or a major paper, many students put in a lot of extra study time in order to prepare.
Does that extra study time help performance in school?
The most important result, though, was that when students lost sleep because they spent extra time doing schoolwork, they had significantly more problems the next day than when they got their typical amount of sleep. This negative effect of extra study time was strongest for 12th-grade-students and weaker for the 9th- and 10th-grade students...
It is an age-old tradition to cram for exams and to finish papers at the last minute. There are lots of good reasons to want to avoid cramming. For example, cramming for an exam may help a student pass that particular exam, but information learned the night before the test is not remembered in the long-term as well as information that is studied over several nights. If cramming for a test also reduces the amount of sleep a student is getting, then that just adds to the problem.