I found this rather interesting community while looking for more information on ENTPs. After reading a thread that lead to a discussion on Heinlein, I knew I had to join. I'm supposed to be an ENTP, but I believe I was classified an ENTJ a long, long time ago. Twenty years ago at least, so I was wondering if anyone had the or even an answer to my current question. Do types flex back and forth and if so, why?