Abstract:   The Importance of Being Eccentric The dynamics of bodies on eccentric orbits largely determines the evolution of planetary systems and stars near massive black holes. In this talk I will review eccentric dynamics and demonstrate wide-ranging implications such as the orbital clustering of Kuiper Belt objects in the outer solar system (which motivates the planet nine hypothesis), ‘ double’ galactic nuclei, and the tidal disruptions of stars by massive black holes in post-merger galaxies.