yes, twice, and both from skiing.

The first time, I was going to do a trick off a small 5 foot tabletop, and as soon as I left the ground my left ski fell off. (those bindings had problems) anyways, I ended up landing directly on my butt, and it hurt SOOOO bad that I passed out for a minute. When I came to they were just about to head off and get ski patrol cause I wasn't responding.

The second time, I was trying to grind a rail on a pair of skis, and as soon as my skis hit, they went flying out from under me. I ended up landing on the right side of my back on the grind rail, and then my head hit the ice near the rail (they only groomed to within 2 feet of the rail). I was out cold for a few minutes, and I don't remember anything from between when my feet came out from under me, and getting on the snowmobile to ride down to the lodge. In fact, I don't even remember the ride, but I do remember getting on and off.

Everyone was concerned about my back (good chance for a broken rib) but it actually didn't hurt at all. I couldn't ski for 2 weeks after that cause they were concerned about a concussion.

@ninjakido
typically you don't remember anything. Not even the pain that knocked you out in the first place. Although, when you come to, you're in pain, but it isn't as bad since the pain has probably started to subside.

lol nordlead. I've had one of my bindings release just as I was making a jump and I actually managed to land on one ski. I was proud, but I needed to intentionally fall anyways so I could recover my other ski.

well, I wasn't just doing a jump, I was trying to do a trick, so when I started to move and my ski fell off, I didn't really have a chance to recover.

But good job landing on 1 ski. I've had enough tough 1 ski situations in my life, (like high speed turns where a ski fell off) so I know how dificult it is.

never once--knocked a guy out but never have been knocked out

Never been knoked out but i knoked out a lot of people..... might seem like tough internet talk but its not :)

During sex once... and never again.

Nope, suffered two concussions but I never lost consciousness. Came damn close once, though. My eyes literally stopped functioning for a few seconds and I only saw colored orbs for a good minute. That was my second concussion.

not me but i knocked a guy out once.

Yeah, I kind of ran into a lamppost when I was 4 or 5.