Originally Posted by
DoubleBarrel 
My understanding is that memories are a higher brain function, and blackouts occur when you are so impaired that you simply don't store any long term memories.
So you are walking talking, basically being you, but you will never remember it.
That's also my understanding. I believe you and VC are correct. It's not that you can't remember, it's that your brain didn't record the memory the way it should have, so there is no memory for you to recall.