We lose certain abilities quite quickly that we have as very young people. The most notable being able to see EM auras on living things. I cant remember how they proved this but I read a credible scientific study about it quite a while ago. Interestingly some people never lose the ability and its one thats possible for everyone with sight to pick up again with certain exercises.
Also a theory I must have read somewhere suggests that so called ghosts and the like are potentially temporal anomalies rather than conscious entities. The
amount of weird shit that can happen in spacetime is something inherently difficult to and not very well researched.
If you think of a ghost as being like an overexposure in a photo, but the photo being the proverbial fabric of spacetime it makes for an entirely different yet plausible explanation.