Well the scariest moment in my life I actually don't remember it. Better off to say it was the scariest moment for my family.
When I was a couple of months old I was diagnosed with spinal meningitis. A very rare disease that attacks your brain and spine. The doc told my parents that if I lived that I would be mentally handicapped, but they gave me a single digit chance of living. The doctor probably would have given me no chance at living a normal life.
I haven't had many scary moments to my recollection. The only ones I recall were my car (Honda del Sol) being only a few inches from flipping over into a ditch and more than likely killing me, or a head on collision I had recently in my current car. Luckily my car was bigger than hers and she broke her arm and I was not injured.
Edit: I was once thrown from a moving car that was only doing about 20mph, not really scary just an intense roller coaster ride.