This paper presents a philosophical analysis of life satisfaction within an existentialist framework by proposing personal synthesis as an ontological imperative. The main argument is that for life satisfaction to be authentically meaningful, a person is behoved by the necessary condition of personally synthesizing the notions, beliefs, ideologies and subjective interpretations they encounter in the world as it were, to ‘solve their riddles and make their own rhymes’. The argument draws on pivotal notions from Kierkegaard, Nietzsche and Heidegger among others, to propose an agenda for achieving human existential satisfaction, in a way that has implications for research, theory and practice in psychotherapy, religious experience, personal development and productivity.