It always seems like a good idea
. A constant temptation
. It's calling, "Come lay on me, I'll keep you comfortable while you study." It's your evil
Although you know what will happen you always end up giving in. You think, "I'll be able to read so much more in the comfort of my beautiful bed." You get off to a swell start. You read a couple pages and think "Hey, why don't I do this more often? It's so much more comfortable than those hard tables and chairs in the library."
Then the inevitable occurs. You begin rereading the same paragraph over and over, and eventually sleep becomes you. You wake up two hours later having drooled all over the GDP and unemployment on page 96. Even though you're fully refreshed from that lovely little nap you still have to read those damn 50 pages for tomorrow's lecture.