Most educators believe that social and emotional learning (SEL) skills are a fundamental part of good teaching and learning. Long before the pandemic, surveys showed that teachers believed these skills were essential for students to learn at school, and research confirmed that they are linked with measures of academic success. Educators need knowledge and skills to intentionally embody, model, and teach the social, emotional, and cognitive skills that enable students to engage in and succeed at academic work. One initiative that is pointing the way is the Partnerships for Social and Emotional Learning Initiative, a multiyear, multisite effort supported by The Wallace Foundation. The initiative provided four years of support and tools, based on research, to help school and out-of-school time programs strengthen students' social and emotional learning skills. Extensive research, including in-depth case studies of the sites' work and participants' development from the RAND Corporation, has illuminated some key lessons about how to make a difference for students. All of those lessons point to the importance of building adults' understanding of and capacity for modeling and encouraging social and emotional learning. One of them emphasizes the need to focus on building adults' SEL skills before implementing strategies to encourage students' SEL development. Together, the findings suggest that professional learning on SEL is an essential strategy for ensuring that everyone can thrive in the classroom--especially in a time of stress and recovery.