Strangely I have had this experience in high school. I was drinking a NOS and eating a honey-bun, minding my own business and half asleep when suddenly a fist made contact with the side of my head. Almost immediately I blacked out, at least I stopped precieving the world, but my body kept moving... For some reason I gave chase (and caught up to him, I was a member of the track team), but I didn't do anything once I caught up to him I just grabbed his arm and stood there not really fully conscious. I had to be told about that later as I woke up in the Sheriff's deputee's office in my school and I was being asked if I wanted to press charges. I said "no" and went on with my day, but that was actually what I did in that scenario, give chase, catch up, then nothing.