Abstract: The self is a feature central to our mental life. Neuroscience investigates the neural correlates of self, which spatially show the cortical midline structure of central importance and especially its spontaneous activity. That leads to the concepts of rest-self overlap and rest-self containment, raising the question how and in what ways the self is encoded in the spontaneous activity and its inner time. Recent empirical studies show that the balance in power between slower and faster frequencies is directly related to the self. Relatively stronger power in the slower frequencies (compared to power in faster frequencies) indexes a stronger self, e.g., self-consciousness, than the opposite with relatively less power in the slower frequencies. On a more conceptual level, this leads us to suggest an intrinsically temporal determination of self which must be distinguished from a-temporal and non-temporal definitions alike as in philosophy and psychology/neuroscience. I thus conclude that our self is intrinsically temporal——the self can be traced to the brain's inner time with its co-occurrence of temporal change and continuity serving as "common currency" between brain time and self time.