Have any of ya'll experienced a concussion while surfing?

I ask because I think I may have just had a minor one today. It wasn't big today, maybe waist to stomach high, but there's an outside sandbar that caused the bigger sets to jack up and pitch. I paddled into one of those, but was really in a bad spot, so I had one of those moments when I thought about letting the wave go and at the same time paddling for it. I was in a really awkward position when the wave doubled up and I got pitched over. I remember getting spun around violently underwater a few times, while the rail of my board whacked my calf repeatedly. No hit on the head. I thought I came out ok, but had a really blurry vision when I surface, and I couldn't even lay on the board to paddle back outside since I kept losing my balance trying to pop on the board. 10-15 minutes later I couldn't even make out the coming sets. I stayed in the water for about another hour, even caught a couple more waves. But the drive home, and even as I type this, I feel a little bit lightheaded.

First time this ever happened. I know we relate concussions to head trauma like getting a bad collision in football, but I believe you can also get one when you get rocked, and even when there was never any impact to your head.

Any similar experiences?