Why do so many diverse cultures share this thing about ghosts being twenty years old? I’ve noticed a common theme in many threads on the SDMB where a person remarks (humorously) that something is the ghost of XYZ who died 20 years ago. For instance, you have SnoopyFan’s comment in this thread. There are quite a few other examples, only I was too lazy to do a search.
Even in India, we’ve had some pretty famous movies with this 20-year thing; Bees Saal Baad (for those in the know) being the most famous of the lot.
So what is it with popular lore about ghosts, spirits and the twenty year gap?
(To the mods: I’m looking for a factual answer here, but a move to IMHO would be fine, if that is YHO.)
A ghost isn’t a disembodied spirit wandering its own haunt; it’s your memory of someone who’s gone. You get reflective twenty years after they leave or die.
Not the hard factual answer you are still waiting for…
Well a common ghost urban legend might be something like the vanishing hitch-hiker.
Person picks up a hitch-hiker and then the pick-up disapears and ya-da ya-da ya-da it is later figured out to be the ghost of someone who died 20 years ago.
You see if a person wearing the clothes of 20 years ago appears their dress does not seem so strange. (at leas here in the US) So if a person was dressed as they were in 1983 the driver would probably think nothing of it. (cept for maye that re-elect Ronnie button but ghosts are never interested in politics)
But 20 years is long enough ago that a random person in a small town would not recognize the dead person right off. If the ghost was a year old the driver may know them or remember the girl killed on the way to her prom last year at this time.
So 20 years is a nice round number that makes the ghost a stranger but not too strange.