Good words, Barry!
I especially appreciate the Keirsey Temperament Sorter. I tested as a INFP (Healer) years ago, and probably continue to be an INFP, even though I am slowly transitioning into an "ambivert" from my familiar introvert status.
I become more introverted when I feel more socially insecure and move toward ambiversion when I'm feeling more self-confidence and higher levels of self esteem -- which fluctuates, for me.
Lately, I'm back to my more introverted ways. But I expect to be more ambiverted in the future -- and hope to be!