No man can teach another self-knowledge. He can only lead him or her up to self-discovery - the source of truth.
Nothing is true in self-discovery unless it is true in your own experience. This is the only protection against the robot levels of the mind.
Truth has to be discovered now, from moment to moment.
Truth cannot be taught but it is quickly recognized by the person ready to discover it.
Self-knowledge is the discovery of the new, it looks beyond the world that has all the answers and no solutions.
You are either ready to discover yourself or you are not. Ready means you have been knowingly or unknowingly practicing self-observation.