...most ghosts are a rag and a bone and a hank of hair at best--a memory fragment stuck on continual loop, just dust and PKE and water-vapour with no real "there" there. Leftover fragments of psychic energy deluded into believing in their own personality; an echo cobbled together from memory and pain, with no self-awareness as such 'cept what we give them. Survival instinct, with no survival.