More children and adolescents today are enrolled in pre-primary, primary and secondary education than ever before. Yet, for many of them, schooling does not lead to learning — and this was before COVID shuttered schools and disrupted learning across the globe, creating an urgent need to reimagine education. A lack of trained teachers, inadequate learning materials, makeshift classes and poor sanitation facilities make learning difficult for many children. Others come to school too hungry, sick or exhausted from work or household tasks to benefit from their lessons. This learning crisis is the greatest global challenge to preparing children and adolescents for life, work and active citizenship.