Abraham Maslow's term, invoked by Robert Greene in the context of Discovering Your Life's Task (Vocation), for the inner signals of what a person genuinely loves — signals that are progressively drowned out over time by the accumulated external voices of parents, teachers, peers, and culture.
Greene treats today's environment as a categorically new obstacle to hearing these impulse voices, not merely a difference of degree: he states he would not have developed the same introspective capacity growing up in today's always-on, externally-oriented, social-media-saturated culture, versus the more introverted upbringing he actually had. The practical implication: hearing your own impulse voice is a capacity that must be actively recovered through sustained inward attention (e.g. journaling, see Discovering Your Life's Task (Vocation)), not one that can be assumed to still be intact by default.