The dreams we collect are like any large sampling of data. At first, it’s just noise.
If something from the waking world enters a dream, it’s natural. If something from a dream enters the waking world, well, that is unnatural.
About a mystical phenomenon (in Germany in the 1920’s, where a few dozen psychoanalysts discovered) their patients were dreaming the same dream. The rivers of Berlin running red (with blood).
