Sounds like narcolepsy. I had a friend and coworker just after college who had that. He could be in the middle of a conversation, in the middle of a sentence sitting up and bang! fall off to sleep. Wasn't out for long. I can't remember how he handled driving but he did drive. He was a cute blond guy that was extremely touchy-feely, was always putting his hands on whoever he was talking to. Not gay, just super friendly. Sure, I'd date a guy like that.