Liu Zi said:
There is a saying that humans, gods and ghosts live in the same space, and that humans' past, present and even future are all at the same latitude. When all conditions are met, the past and future will appear at the same time. The ghost might be playing mahjong with your mother downstairs. When you see the great-great-great-great-great-grandfather that dad described is basking in the sun on the balcony, please calmly walk over and say hello to great-grandfather...
PS: This story is purely fictitious. Any similarity is purely unfortunate.