Invaluable reward gained as a dutiful teacher

Preparation of lecture note is a learning process for the instructor even if he / she have already knew the subject matter for many years. Personally I took the preparation of lecture process a re-learning opportunity to gain new insight on the physics and mathematics already known or unknown to me. Say for example, I know nothing except by name the term “vector space”, “basis set” in linear algebra, or “grand canonical ensemble”, “chemical potential” in statistical mechanics. Now, after lectured to an audience of ~ 100 students in the linear algebra and statistical mechanics classes, I claimed to have understood these things quite well, despite my knowledge on these topics were effectively zero before undergoing the painstaking lecture preparation process. I used to tell my statistical mechanics class that in terms of knowledge gained, I was the person who has benefited the most from my own lectures. Incidentally the knowledge I taught to the statistical mechanics and calculus and linear algebra classes turned out to be very useful later when I embarked on my research topics in computational condensed matter physics. Hence it aroused in me the realisation: the eventual usefulness derived from the teaching process is indeed an invaluable reward to those who bothers to take teaching seriously and dutifully.