I thought maybe I was a repressed or non-higher functioning ENFP. I think there is still some vestiges of social conditioning and negative experiences I'm trying to shake off at the same time.
But -- it's nice to know there is a typological explanation as well. And a new theory I hadn't read up on elsewhere. Thanks Nemo!
I also think my ideas of 'extroversion' are very American culture based on classic ESFJ or ESXP archetype. I definitely do a lot of sizing up and observation when I first meet people and am put in new situations and also believe in propriety to a greater extent than my age peers. And it's true, I don't feel my switches being flipped on all the time. At the same time, there are definitely situations where you have to rein in the ENXP-ness or just get looks and people slowly backing away from you -- just like how any type or person has to modify themselves to get along in the social world.