Let's suppose that there are infinite level 1 universes, agreeing with physicist like Max Tegmark and even before them with philosophers like Giordano Bruno.
Now, please follow this thought experiment: I'm in the universe #1 (U1), I'm ten years old and unfortunately I die in a car accident. The Universe 2 (U2) is almost identical to the first one, but here I escaped the accident at the last minute. At the age of thirty, however, I die of a sudden fall. In U3 I avoid the fall and survive, only to die at fifty for poisoning, from which I recover in U4, to die ten years later for an heart attack, from which I recover in U5, to have a fatal tumor after another ten, from which I recover in U6 ...
If there are infinite universes, do very old people have to remember many mortal risks, more and more frequent with age? In some other very rare universes, are there very old people, almost immortal?
Moreover, if we believe that we are the same person even after a long deep sleep, a coma or an hibernation, the continuity of our consciousness should therefore last a few centuries? The case described above implicate differences in components (body) and place, so it's not qualitatively different from a case where I fall asleep for some years and someone move me to a colony in Mars and wake me up: the body components changed and the place as well. Similar issues are raised by the teletransportation paradox.
PS: Note that I'm not speaking of Quantum immortality, that requires a level III multiverse
Someone wants to close this topic as OT, but in the Physics SE told me to come here, and I think they are right, this is philosophy of science.