Teaching is Learning
" 'Good' teachers often continue updating their portfolios throughout their entire career."
As much as I hesitate on the word 'good' (as opposed to 'effective' or 'experienced')—since 'good' is a "lazy" word, and does carry moral implications of 'good versus bad'—it is perhaps appropriate in the context of mentorship, and embraces a philosophy closer to what I conceive and appropriate, namely:
Whatever subject you choose to teach, learning is secondary to teaching itself.
This concept was introduced to me by an?[indigenous]?Bolivian professor* who gave a university lecture to introduce a Bachelor's in Pedagogy of the Mother Earth (Madre Tierra ). His speech underlined that 'teaching is learning' and that learning how to teach, therefore, involves none other than learning, as it involves knowing how to impart knowledge onto others, to future? generations.?
That one lecture completely changed my view, and I came to realise only much later that his speech made the distinction between teaching and imparting wisdom as it stuck all this time.
REFERENCE:
Talk in Spanish with introductory incantation to Pachamama :
* Prof. Alexander Yarza de los Rios, Nov 6, 2014, at Berne University for Pedagogy.