Only 20 percent of a child’s waking time is spent in school. That means that even with the best schools, the best teachers and the best educational policy, schools cannot close the achievement gap. To be sure, mountains of research demonstrate the significance of early schooling in changing learning trajectories for young children. With 25 percent of the population having 10 or fewer age appropriate books in their home, high-quality preschools offer exposure to reading and to the rich language conversations that support literacy. For children rarely exposed to puzzles and blocks, high-quality preschools grow the spatial ability that will promote strong STEM skills in science, technology, engineering and mathematics. For children who are not read to or talked to or encouraged to control and channel their feelings constructively, preschool helps them to develop the self-control they need to profit from further schooling. High-quality preschool prepares children for entrance into formal schooling. But preschools cannot do it alone and preschool failures cannot be blamed for the persistent gaps that have plagued American education since 1975. Perhaps it is time to augment debate about universal preschool with discussions of how to build learning communities that enrich children’s experiences at home, in school and beyond.