A solid way to master a topic is to provide a training on it. As a teacher you think through the logical flow of your “class”, so that students will achieve their goals. You preview your students and you assess their current knowledge level. You anticipate questions and you think of answers. That in itself may bring you new insights. During class you may learn new insights on your class and topic too. Some students actually know a lot about your topic already. And they will probably bring new topics to the table. Meaning you will learn of lot!
Better every day 