On Tuesday, after morning work was complete, students were offered some choice activities. All thirteen students chose to explore trains together. With interest and curiosity I watched and listened as they began playing together. Would they be able to make this work with all thirteen of them? Would I need to intervene? How would they manage the demands of decision making and sharing? As students began to transform the rug area into a new world, it was clear that this activity extended beyond playing: they were practicing the key skills associated with 21st century learning. Children used critical thinking to solve problems they encountered while building. They communicated their needs and ideas and used their words, bodies, and voices to persuade, celebrate, and rally their peers to the shared task of creating. They did more than play alongside each other; they collaborated by using one another’s skills to move the group towards a common goal. These four skills are defining traits of 21st century learning and ones they will carry with them and use throughout life. Maybe the saying “All I really needed to know I learned in kindergarten” is truer than we realize!