No amount of scepticism and criticism has yet enabled me to regard dreams as negligible occurrences. Often enough they appear senseless, but it is obviously we who lack the sense and ingenuity to read the enigmatic message from the nocturnal realm of the psyche. Seeing that at least half our psychic existence is passed in that realm, and that consciousness acts upon our nightly life just as much as the unconscious overshadows our daily life, it would seem all the more incumbent on medical psychology to sharpen its senses by a systematic study of dreams. Nobody doubts the importance of conscious experience; why then should we doubt the significance of unconscious happenings? They also are part of our life, and sometimes more truly a part of it for weal or woe than any happenings of the day.
Carl Jung, “The Practical Use of Dream Analysis” (1934). In CW 16: The Practice of Psychotherapy. pg. 325