Well I haven’t read extensively, but I can believe that you’re an INTJ :) My flatmate (who has a behavioural science degree) informed me that the little tests you do on the internet aren’t the real Myers-Briggs Test, and the actual test is pretty well-guarded so it doesn’t lose it’s accuracy, which is pretty logical I guess.
Half the time the descriptions of the types seem a bit like reading a more accurate horoscope. If I’m going to describe myself succinctly to people I’m going to use MBTI over horoscope any day though :P
INTJ is the one of the four IN types that I'm furthest from if I look at percentages. INTP and INFP are very very close though.