Self-tracking by means of digital devices has become a common practice during the last decade. By investigating this most recent form of self-observation, which can be situated within the context of the Western history of the individual, this essay will discuss the consequences of quantification as well as of contemporary neoliberalism on the formation of the self. At this moment, I will argue, we have come to a point where the stress on individualization has reached a tipping point: even the most intimate has become public and is controlled and used by agencies often unknown to the individual person, thus contradicting the concomitant claim of freedom of choice. This is particularly evident in U.S. culture and society which, according to surveys, is globally the most individualistic culture. The concept of “the Quantified Self” will therefore be examined in regard to contemporary paradoxes of self-knowledge and self-formation.