The psyche can be occupied by symbols and archetypes that we are unaware of. Being undiscovered, they are free to affect our behavior unconsciously and therefore without our consent. Thus one of the goals of Carl Jung's "individuation" is to uncover these entities and gain control of them.
An archetype particularly resistant to discovery is that of our own Self. The Self is the innermost reality of a human being. It is the totality of all the moving parts of the psyche; contents that have been rendered awake by consciousness, and contents that have not been revealed. According to Jung, the Self is a functional equivalent to the God archetype. This, for me, means the Self creates its own reality and is capable of revealing its own functioning as the quantum reality giver. When we become aware of the Self, it seems like the Self is exposing itself. Awareness of the Self seems to emanate from the Self, and not from any autonomy or achievement by the individual. Thus the Self is at least partially unknowable for almost everyone.