I had full blown altitude sickness once. Normally when crap happens, I can look back and laugh. That wasn't such an experience. It's pretty horrible.
^ Exactly. Had it happen to me out of the blue many years ago. Ended up with lungs full of fluid and a short stay in the hospital, could have ended badly. I was healthy as a horse and had been at altitude many times with no issue, just happened out of the blue.