One can have all the knowledge in the world. However if we can't teach it on effectively we aren't suitable instructor material. There is also a lot of phycoligy involved in effective instructing CRM and Captaincy, for example, IMHO.
The day we stop learning and think we know it all. Is the day too give it up.
Excuse typos etc. I was born with a limited amount of brain cells. I will be f&&&ed if I am going to waste any of them on unnecessary absorption of rubbish.
You cant teach ability, flair or aptitude.