Blackout experiences

No, I'm not talking about the metallic beast from Transformers.


Have you have gotten a blackout as in lost conscious?
If yes, would you mind telling us what it was like during that time you were out? That is, if you remember...

For me, I had a bicycle accident a few years ago. It was downhill and I was going very fast.
From what I can remember, it was all black in empty space. I did hear some noises around me, but I couldn't figure out what the noises were.
I woke up a few hours later with a alot of people around me and somebody told me that I kept asking what day it was :|

Jam it back in, in the dark.