Great insight, it actually aligns with the conversation above: Yes, teaching is its own skill regardless of the subject matter, but to teach you really have to understand the subject matter really well, and isn’t at all related to “doing it well” in some cases.

For example, in film, being a great director requires a deep insight about acting, so they can explain what’s needed from a performance to an actor. A director may know what they need despite being unable to perform it themselves.