Building on theories and research findings related to educational interests, Anke Grotlüschen explores how interest develops and evolves, discussing the conditions for a renewed theory of pedagogical interest. The work is based on pragmatic, subjective scientific, and habitus-theoretical frameworks, leading to a two-axis model of interest genesis. Three empirical approaches support two central theses: interest goes through the phases of latency, expansion, and competence (phases of interest). It develops and dissipates only slowly (interest inertia). The author demonstrates that the emergence of learning interests and learning resistances is related to the surrounding world in a differentiable manner. Nevertheless, they are also inextricably linked to a subjectively felt sense of self-determination. Both elements—the external stimulus and the subjectively experienced self-determination—are essential.