Thrice:
1. 2002 - I was rummaging through a drawer and somehow, a knife kinda poked through my wrist. Ouch. I was able to call out to my mother just before I collapsed in bed. There was no blood loss but the sensation of that cold blade...brrr!
2. 2004 - I witnessed a pretty gruesome accident. Dude's head cracked open and died in the middle of a busy street right in front of my eyes. After the police/paramedics arrived and things started to fall to normal, I got on my bike, drove for about 10 seconds, got off the bike, sat on the curb and passed out. I have no idea HTF that happened.
3. 2004 - Had a seizure (I think that's what it was) three years ago for no fucking reason. The doctor in the ER thought it might have been because of fasting (it was Ramadan) but I am pretty sure that had nothing to do with it. If you are hungry/exhausted, you just drop to the floor, right? You don't flip out, flail arms wildly and bang your head repeatedly on the dinner table as both your parents try to restrain you. That was the first and last time that happened to me - I should probably have that checked out, eh?
I sometimes feel like I am about to pass out - it usually happens when I am witness to particularly violent things, usually road accidents. Gore, blood n' gibs in movies/games don't bother me but watching a paramedic haul away a lifeless, limp human being whose face is obscured by pints of blood - it always causes the same reaction.
1. Things start to get blurry.
2. This hollow echo starts to drown out all ambient sounds. Someone standing right next to me starts yelling, "Dude, you ok?" right in my ear but it sounds like a faint sound miles away. It's like being shell-shocked, I think.
3. I sit down and tuck my head between my knees, eyes shut and ears covered with my hands.
4. In about a minute, all is normal again.