“Who looks outside, dreams; who looks inside, awakes.”
— Carl Jung, Letters
What this quote means
Jung's case for the inner work of individuation. To "awaken" is to confront the unconscious — including the Shadow — rather than seeking meaning only in external achievement.
The idea behind it
The Shadow — Jung's term for the disowned parts of the self — traits we deny and project onto others — which must be integrated to become whole.
From Jung's collected letters; attribution verified. Confidence: high.