[Spoiler] Brain scan question.

[Mudbill]

I think of it as the game switching perspectives, not as memories. But rather than switching perspectives, a better explanation would be how Catherine explains it during the Abyss Climber. That she just snaps in and out of existance. It's like sleep, but instantaneously and without dreaming. Therefore I think that, although the game of course could've taken the perspective of Simon 1, it chose not to for the sake of itself. At the time when Simon is first scanned, his story is split. His person is split that very moment, even if Simon 2 doesn't wake up for another 100 years. That's how we experience it as a direction continuation of his previous life. Simon 2 merely slept for 100 years instantaneously.

And for the sake of the infamous "coin toss," although not a real thing in the game, it is a thing in the gameplay. It's a predefined coin toss of which of Simon's consciousnesses we continue as. It's like an alternate universe. The past of Simon scews out into its own path, while ours is chosen by the player.