10th grade PE dodgeball. Collided with another kid with brief loss of consciousness. Went to English class next period and could not stay awake. Walked out of class with a couple friends and got suddenly very nauseous and didn't quite make it to a garbage can in the middle of a busy high school hallway. I still have the memory of my "friends" bolting the second I threw up but to their credit they actually went to get a janitor.