As physicist Richard Feynman advocates, the best way to learn a subject is to teach it to a toddler. When we try to solve problems, the depth and completeness of learning is limited if we stop at the moment the problems are solved. When we explain the problem to others, we start of journey of deepening and refining our understanding. Writing docs is an on-paper counterpart to teaching. This talk shares a journey of learning as I write the docs for React Redux, Docusaurus, as well as maintaining my own notes on Flow.