Though I do admit to not haveing all of the answers to 'Big O'. What I have come to realize is what is said through out the series, 1 and 2. That there was no past, no memories forgotten. How could people lose memories when they never had them to begin with. This entire world revolves around 'Angel'. Her love for Roger, and her quest to find out what the Man was like. What happened in that timetable. Though if angel was an angel, then she was dead. Just her spirit wanting to ask what happened to humanity? As said in the series she was a Memory. Just her. So therefore is it possible that her world, the one she created was just a memory of her memory?
The last episode reminded me of the holo-decks on Star-Trek! Where people would create worlds for them to play and relax in. They could create other people who didn't know that they were just a memory, just a hologram. Same thing with Big O.
One question that still haunts me. Why at the very end does the story start over again? Then I think and imagine what it would be like to be a character on a DVD. The DVD we watch, we play it over and over again. Angel may have been replaying those events one after another to try to find a different ending to the series. Or to find any lost bits of memories prior to that series. That would explain why Roger kept haveing flashbacks.
Who was the Operator? Mentioned in the last episode. Was is Angel? But if Angel wasn't the 'Operator' then who was? That is the biggest question of all. (Reviewer: Peter K. Peers)