Why am I tired today?

I fled bar review at 11:30 and went right to bed. Why am I bleary-eyed now?

a. I woke up at 5 to do my source & cite.
b. 3 am booty call.
c. At 2 am, my roomates stumbled back from bar review and proceeded to have a loud argument about the meaning of "art" in the living room and kitchen until 6.