u/FaxMachineMode2

The theory says that when you might die, multiple universes are created: some where you die, and some where you don't. Because you won't be there to experience the ones where you die, you will just keep always experiencing universes where you survive. However, the universes where you die will still exist and continue on, full of people. So the only effect of quantum immortality you could ever experience is with regard to your own life. If you meet someone with a near death experience that sounds like the result of quantum immortality, that doesn't count as evidence for you, because whether or not they live doesn't affect if you can see this universe. Quantum immortality argues that for your perspective, you will be the only person affected by quantum immortality. Any evidence or anecdotes people share are by the nature of the theory a coincidence. So if the idea freaks you out, don't let anecdotes scare you more. Also if you are deeply troubled by this, please look into ocd. Obsessions with unknowable ideas are a common symptom, so if this messes with your life too much that is likely a symptom of a mental health issue