Psychological theory is a best guess. At best. Now, I like the MBTI and it is my personal opinion that it is one hell of a good guess, but it is nowhere near being an absolute truth. If there were to be an absolute truth, the letter-code for a personality type might be a million letters and/or digits. And then it would hardly be useful anymore.
MBTI is a great sketchy rough outline of people as they tend to be. Love it.
To the point, though, I believe that type is not constant. People talk a lot about "shadow type" and such. Except that I do believe that people can change. Especially after they've been through something of a personal hell. I changed a lot during a period of five or six years. Can't say i'm anything like I was before that physically or mentally. I was a very friendly INTP. I kept to myself a lot as a kid and I had a bunch of abstract interests wich I seldom shared with anyone. Pretty detached from the physical world. Very T... Began evolving my Feeling functions when I was about 17, before that I was almost constantly annoyed with the world lacking in logic and that everyone seemed to be unable to detach themself to see the big picture.
Circumstances made me more ENTJ/ENTP-like, at least at this point in life. I'm not going into it but there were pretty severe psychological trauma involved, really should have seen a psychologist, but I never did. And I turned out a wee bit crazy, but mostly intact
