Idios kosmos
Idios kosmos (from Ancient Greek: ἴδιος κόσμος) is people's "own world" or "private world" as distinguished from the "common world" (koinos kosmos). The origin of the term is attributed to fragment B89 (Diels–Kranz numbering) of the pre-Socratic philosopher Heraclitus: "The waking have one common world, but the sleeping turn aside each into a world of his own." The term has various interpretations: idios kosmos is associated with dreaming, imagination, and delusion; koinos kosmos with wakefulness, reason, and consensus reality.