Consistent with predictions derived from the self-expansion model, this 3-year longitudinal study found that participation in more college groups during sophomore year predicted increases in inclusion of the college community in the self at the end of junior year, which further predicted increases in satisfaction with the college experience at the end of senior year (full mediation). This study offers college community connectedness as a theoretically grounded mechanism to explain why extracurricular involvement is such an important piece of the college experience, confirming what student affairs professionals already know: connectedness matters.