Say it with me people; Withdrawal.
I may look catatonic, but on the inside I'm beeboping and pulling my hair. Promise.
It's like my brain is trying to freak out on my body, and considers it, very carefully. It decides on a certain chain of events and plays it inside my head. But I'm too tired to freak out. So my body just sits there.
My brain subsides for awhile. Then everything starts all over.
You try doing that 3 times/minute. Asswipe.