My immediate reaction is Occam's Razor makes the idea of multiple distinct selves pretty unlikely.
That's not the way Occam's Razor works. The quantity to minimize is the number of bits needed to specify a theory, not the number of objects the theory describes.
There are multiple humans. Taking the arbitrary number of humans alive at anyone point, and saying that census data must be faked, and that there are only as many humans as I have direct experience of, would be shitty application of Occam's razor.
Saying I have a second "self' without giving evidence of the self, without any specifications of what that self would be like, and how that's different, behaviorwise, from a human with one self, and how that gets us more explanatory power for our postulated entities, is exactly what Occam's razor is for,
I me...
http://www.smbc-comics.com/index.php?db=comics&id=2705
Addresses questions like "If I don't remember, but it definitely happened... who suffered?" in a rather non-obvious way (non-obvious to me, anyway).