Sleeping and dreaming are mysteries for most of us: events that occur daily, but about which we know little. This is an interesting insight. (A slight aside: discussions about what "nature" and "evolution" have "done" are anthropomorphizing errors. By definition, "evolution" is a theory, not willful process; we may explains certain events by evolution -- macro or micro or both -- but "evolution" does nothing. Ditto "nature," which we often use to avoid saying "God.") The video is in English, but has subtitles -- Dutch, I'm guessing.