Could a person die but not know it?

Could it be possible that you have already died and not know it and continue living on as a soul or spirit but in reality you have passed and your soul is stuck and has no idea? could also explain “ghost” hunting places where they have died. I’ve also read in the Bible under Ecclesiastes 9:5-6 “For the living know that they will die, but the dead know nothing” implying that the dead probably don’t know of there death or of anything.

Could a person die but not know it?
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