They say that when you die, your brain floods with DMT, the chemical of dreams. Your perception of time slows and you relive your life as synapses die and memories pop into being one last time. Memories are fuzzy and imperfect things, and in your psychedelic dreamscape your life plays out a little bit differently. Then, your dreamscape self dies, and it floods with DMT, and so recursively, at the moment of your death, you dream and live your entire multiverse of selves.
These recursive multiversal selves exist in a metaphysical space, a space of souls, where the soul-self opens the gate of the pineal gland and enters the collective unconscious.
And what are undead, if not liminal beings, a physical, synaptic consciousness at the gate, lacking a soul, the apparatus to join the collective unconscious? Zombies don't hunger for brains, they hunger for souls. But no matter how hard they try, no matter how many brains they consume, they'll never be able to digest, to integrate, the soul. Weep for the pitiful hungry zombie. Vampires, lich lords, and other intelligent undead sleep, but without a soul, what do they dream?
They do not relive their lives, but the lives of those whose brains they've eaten, blood they've drank, bodies they've necromantically revived; damaged and mutated, the undigested souls linger within, propagating through a dark multiverse of astral un-life, the reciprocation of undeath, a limbo dimension of null that exists, cruelly, to balance the physical inequality of energy that undeath introduces into the universe. The undead dream the purgatory of the living.
Also, I made my first post on the collaborative blog Iconoclastic Flow!