When I was in college, while I stared at my computer screen, my first year roommate watched me as I lifted a can of coke 6 inches away from my lips and tipped it, pouring at least a third of it into my lap before I noticed what I was doing.

My roommate laughed in such an out of control spastic freakout that I thought that he was going to start throwing up. He would point at me then at his chest, laugh, stop breathing and fall to the ground. He repeated this laughter over the next three days. I was annoyed until he pointed out to me what it really looked like, at which point I thought that it was as funny as he did.