The lecture, based on the homonymous book of prof. Delia Steinberg Guzmán, held by the New Acropolis in Bucharest, focused on various aspects of self-knowledge: the need for sustainable achievements, the ability to identify valuable goals in life, to recognize personal problems and find solutions to them, to identify the strengths and overcome the weaknesses in order to become a better and moral person. A more profound inner life could be a key to act proper as a human being.