After a brief overview of the “three ways of seeing that liberate” (into anicca, dukkha, and anatta, or impermanence, reactivity or suffering, and not-self), and how to practice investigating anicca and dukkha, we explore a practical way to understand and investigate anatta or not-self. We focus on two ways of investigation: (1) noticing when the sense of self is “thick,” and studying it; and (2) learning in a number of ways to be with the flow of experience with less or little or no sense of self, as we “thin” the self.