Why is it "An Exhausted Mind"?

For some strange reason, I've been waking up around 4 or 5am the past two weeks or so. Given that I am often going to bed around 11:30pm or midnight that isn't really much sleep to be functional, despite the U.S. Army guidelines. If it is a class day, which for me is 6 days a week :-(, that means the alarms goes off at 6am. I've noticed that upon awakening I never really fall back asleep.

I'm thinking of using some Tylonol PM tonight and going to bed early. I've already got the reading assignment for tomorrow done because Monday's Admin Law class was cancelled. I would like a decent amount of sleep for a change. The caffeine IV going into my arm is getting noticeable to others.

How much sleep does anyone else around here get lately?