In the space of time I lost my memory I was functioning, my friend got me across the NY subway and out and we were walking back to the hotel when I realised that I'd just missed an hour. I was in the bar and then suddenly I was nearly back at the hotel, that's how I remember it. It's never happened before or since.

Usually no matter how drunk I have been, I can remember everything (except perhaps the fine detail of what I was saying.)  I have friends who have the complete blanks quite frequently but it's the only time it ever happened to me, I was just astounded by it.

Ad astra per aspera