TL;DR
Just an idea/theory.
Brain death unfolds unevenly, with oxygen deprivation affecting neurons variably based on their proximity to capillaries, leading to a staggered cellular shutdown. As cells die, they release a surge of neurotransmitters from vacuoles, potentially triggering a chaotic replay of encoded memories across the neural network. The Default Mode Network (DMN) may hyperactivate during this process, fostering intense self-reflection and a timeless summation of one's life experiences. Endogenous DMT could amplify this, creating psychedelic visions that mimic near-death experiences, blurring the line between biology and perceived eternity. Subjectively, this internal storm manifests as an afterlife-like odyssey, even as objective reality registers complete cessation.
I'd imagine that the dying state emotionally reflects the comparative weight of all encoded memories with emotions, where if you lived sour, your brain doesn't have the spectrum to support something like
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