I don't know if this is more a question for physics stackexchange or philosophy stackexchange, but if the theories behind quantum immortality are true (eg. Many worlds interpretation), why does it imply we live forever.
I understand the idea that in most near death situations, there is a reality where you live, and a reality you will die. And I accept that one cannot experience their own death because it implies the death of their consciousness. But I do not understand how these two facts combine to create "we live forever!"
It seems the "you's" in all realities ( if the many-worlds interpretation is true) are separate entities with their own subjective experience. So what guarantees, that if you are in fact in the reality where you die, that version of you will not just come to an end, and the consciousness will just be gone forever, and that version will just experience oblivion? Why would it instead start experiencing the reality of a whole other version of itself, if it seems all versions of oneself are separate entities?
In other words, if "I" die, as in the version of me who is writing this, my individual consciousness, separate from all the other consciousnesses out there that are other versions of "me," what reason do I have to believe that I would not just experience oblivion, as my consciousness disappears, but somehow have me, my personal consciousness, start experiencing the universe of a whole different consciousness?
I have a feeling we cannot make the assumption that "we" will live forever, seeing as we don't really know if the other you's are the same consciousness as us, and if we could really experience what they experience. That's making too many assumptions about personal identity that we have not proven, philosophically or scientifically.
What's more, what guarantees that there really is always a reality where you live. What about situations where the universe as we know it ends? There is no way you could not die. Unless, of course, we are implying that that situation will never even arise in the first place?