As far as I know from mediums...
You don't
know anything from mediums. You freely admit there are people out there merely pretending to be mediums. And you admit you can't tell the difference between them and the people you're citing as authorities. How does that result in knowledge? Your information is literally no more reliable than what I hear from the man on the train platform who's talking to a bench.
Anyone that dies does not automatically have access to memories of past lives.
But this whole hokey religion is based on people maintaining their former personalities in the spirit world such that mediums can use the personal appeal of some spirit to instill faith. You have American Indians and Chinese spirit guides and so forth, all lending an exotic air to the tale. If they stop being who they are once they die, then the whole religion collapses.
But as a rule only enlightened souls that have completed their cycle of incarnations have full access to memory of past lives.
But then there's your little skirt-chasing brother Lawrence, who obviously hasn't reached ultimate enlightenment, yet who not only has the memory of his former life -- brief and insignificant as it was -- but is allowed to talk to you about it. As usual, your spirit world is full of contradictory principles of operation and
ad hoc exceptions.
In these dangerous times the spirit world would doubtlessly like to comfort as many people as they can. But belief remains largely a matter of faith. The spirit world are unlikely to give absolute scientific proof of their existence, as that would interfere with the worlds karma.
You didn't answer the question. You just repeated the dilemma you were asked to resolve. Gullibility remains largely a matter of faith, too.
The magician includes a few steps that supposedly preclude the accomplishment of the illusion by ordinary means. He shows you the apparently empty hat before pulling the rabbit out of it. He opens the little window to show that the newly bisected woman is still apparently inside the box. Your self-proclaimed mediums do the same thing, proposing to accomplish things you believe can't be done by ordinary means. They attempt to convince you by ordinary rational means that their gift is real. They've invited you to tell yourself that your belief results from a critical process, not blind faith. But now that you're being shown an actual critical process, you balk and return to blind faith.
There's no such thing as "absolute scientific proof," so quit battering your usual straw man. There is merely evidence that survives rational examination. You have none of that, but your mediums are frantically trying to convince you that they do. You maintain that science is incomplete and that its methods of investigation are limited and flawed, such that it can never understand your beliefs. But your information is merely
ad hoc hearsay that makes absolutely no sense. Your inability to paint a coherent, uncontradictory picture of this place that you claim is real has a much more parsimonious explanation: it's all made up. Mediums are poor storytellers who can't keep the details straight from story to story. And you've fallen for it, hook-line-and-sinker.