The person who learns the most in any classroom is the teacher. Passively taking a course or reading a book is the first step. If you want to learn a topic at a deep level, then teach it to others. The challenge of teaching and sharing your knowledge will force you to learn the ideas with clarity to easily explain them to others. Thinking about the questions you will get from your students will identify areas that require further learning on your part.
Jon, thanks for the insight. There are so many ways and opportunities to teach in a typical day. Teaching is a lifelong pursuit!