It’s an interesting thought. I don’t recall dreams anymore. When I was younger I can recall the environment around me causing effects in my own dream. So one might in deed know they die while dreaming depending on how that death occurred from this point of view.

I find the afterlife a rather crazy thing to think about . My sister’s kid recognized his great grandfather who has been long dead before the kid was ever alive. Oddly enough he called him grandpa since he did not know better. Pick him right out of an old photo from a family reunite, and said he sometimes visits them. I just dint see too much of a realized between grandpa and grandfather to think the kid picked up on it that way.

Then we just have the oddly bazar things happen. Family members seeing halos over their birthday cakes in photos that do not show up when its printed, and smoke alarms randomly giving a larger than normal single BEEP and then acting normal again while walking past them.