One of the things I've realized in life is the best teachers are people who were not very good at something and then became very good at it through sheer practice and grit.
People who are naturally gifted at something because they can't understand the reason for someone else's failure can't teach well.
I worked for a year of work study as a math tutor at a community college. "How to do integration by parts[1]?" one student asked? That's easy to explain. My hardest day was when I was trying to help this one woman understand that when you multiply two negative numbers you get a positive numbers. "Wouldn't that make it more negative?" she asked.
I decided I would have been a terrible math teacher even though I was very good at math. And reading this article was interesting to me because it explained to me why I would be a terrible math teacher.