I investigate the long-term effects of after-school childcare on children's human capital investment. I exploit the timing and intensity of an after-school care reform in the Netherlands, and build a 20-year panel with administrative data to track affected cohorts from childhood through adulthood. I find that university graduation rates increased by 8%, with the strongest impact among students from less educated families. This effect stems from higher after-school care use rather than maternal employment responses, highlighting childhood environment as the key mechanism. I consider three potential channels: improved skills, stronger preferences for university, and shifting beliefs about returns to university. I find evidence supporting changes in preferences and beliefs as the main drivers, rather than skills. I show that the reform increased exposure to peers from high-SES families in after-school care, potentially driving these changes.