We learn best by returning to the same content over and over, reflecting on it each time to deepen our understanding. This is because knowledge is stored as patterns of neuroconnections in the brain, and those connections are strengthened each time that pattern is activated by using the knowledge. Thus, “retrieval practice” hardens the learner’s knowledge, making for greater retention. It also allows the learner to see new connections between the knowledge and related knowledge, which expands and deepens their understanding.