Have you ever fainted? Like full-on all of a sudden your body just forgets how consciousness works fainting?

I had it happen to me this morning. I was just there talking to my mom, and suddenly my vision started to go dim, and I couldn't keep my balance and started just staggering trying not to fall over. I fell into mom, who caught me and helped me over to the couch, and I sat there for a few minutes before the sweating and the ringing in my ears went away. Ten minutes later I was totally fine, like it had never happened. Still have no idea what caused it. I don't think it was hunger or tiredness, I'm not sick, and I'm definitely not pregnant...

Has this ever happened to anyone else?