Have you ever experienced this? The exams are coming, probably, you have searched and found your Textbooks, and after possible amount of procrastination you open it and read a few lines. Suddenly you’re overcome by the neediness to put down the book and go to sleep? It doesn’t really matter what time of the day it is.
So, there’s obviously something about Textbooks. I don’t really experience the same when I start reading something which has no relation to my studies. Maybe someone ought to do research on this “Textbook Sleep Syndrome”.
Concentration is Interest; And Interest is Everything.