I took a test, I don't remember which one, when I was 15 or 16. It was actually my mom that found the MBTI first, and she was curious about everyone in the family, and administered the test the pencil&paper way. I came out INTP. The profile sounded accurate to me and everyone else in the family said it sounded like me, so I stuck with it.
Ever since then, I've been interested in the MBTI and studied it. I've taken many different tests, of varrying quality, and come out INTP most of the time with INTJ being the occasional other result (I've gotten some other odd results, but usually from very odd tests). I've piled over so many profile descriptions, and various theories about the MBTI (I ultimately stick with Lenore Thomson's way of looking at it the most) but time and again, I find that none of the other type profiles work for me as well as INTP. It's not so much a matter of inclusion and exclusion. I'll think maybe I'm not an INTP, and then rule out every single other time, and conclude I'm INTP again. Doubt never lasts long.
Putting the type profiles aside, and looking at it more from the cognitive processes alone, it can be a little harder to tell (mainly because quantifying the use of functions is always rather fuzzy). I still think Ti-Ne describes my style of thinking best. I think the ones I alternatively considered the most were Fi-Ne at one point, and then Te-Ni at another, but I think Ti-Ne checks-out more.
At this point, I've decided there are so many serious flaws with the MBTI that I question whether or not it is in a state to reliable assess anyone. Never the less, that's a question of the whole system, and not any particular dynamic that would make me INTP. So I stick with INTP, but I'm less attached to the idea of having any type these days.