To Jesse: You apparently completely separate the probability of x and x'
from the similarity of x and x'.
I am not sure that makes sense for me.
In particular how could x and x' be similar, if x', but not x, involves a
'white rabbit events'.
It's not completely separable, but I'd think that "similarity" would mostly
be a function of memories, personality, etc...even if I experience something
very weird, I can still have basically the same mind. For example, a hoaxer
could create a realistic animatronic talking white rabbit, and temporarily I
might experience an observer-moment identical to what I'd experience if I
saw a genuine white talking rabbit, so the "similarity" between my current
experience and what I'd experience in a white rabbit universe would be the
same as the "similarity" between my current experience and what I'd
experience in a universe where someone creates a realistic hoax. I don't
think the first-person probabilities of experiencing hoaxes are somehow kept
lower than what you'd expect from a third-person perspective, do you?