This train of thought has to have something to it. There is obviously something that is "the same". Perhaps it is something more fundamental than the photons th

This train of thought has to have something to it. There is obviously something that is "the same". Perhaps it is something more fundamental than the photons that "generates" the photons. Or, if it doesn't "generate" them, it determines the state of them at least. In "Many Worlds", the "something" would be the particular universe that "this instance" of ourselves ended up in.