Individuation was a term coined by the psychologist Carl Jung. For Jung, individuation is the process of becoming aware of ones true self; beyond the conditioned conscious mind. Jung believed that through accessing our unconscious mind (which effects our life unknowingly) and meeting with our shadow, we could become fully integrated individuals living connected to all beings..
This can be a psychologically and/or spiritually painful process as we have many hidden (shadow) parts to our psyche that we prefer to keep unrevealed (fear). They have often been rejected in childhood by family and/or society and therefore have been repressed. Self realisation requires a meeting and acceptance of our shadow self.