>If you want to be good at activity X, you have to start to see yourself as an X-er – to act like an X-er.
This is what struck me the most. It's a terrible generalization (beyond the limits of a mathematicians competence) that doesn't hold up - you can be good at any given topic without actually identifying as anything. Since I have no degree in psychology, I'm in no position to actually claim to know better. That being said: the notion that identifying with anything somehow enables you to reach deeper ends of a field is simply off. Afaik, identifying with anything is more a blockage than anything else. Also, the mere fact that he is an educator is meaningless to me in this context, as some of the most ignorant/filled with hubris people I've come across can call themselves educators, so if anything I take that term as counter-indicative for general competence.
That being said, I may have judged too harshly given that I missed the clarification in the last paragraph.