I had toyed with the idea that I might be one one a few times as well. The big difference between me and the INTJ's I know is usually that a) tons of details don't seem to distract them from the big picture, and b) their aim is towards efficiency (whereas my mind is all about the implications of this and that on people). Mechanically minded is probably the best I can describe it. Those are 2 big no's for me, so that's how I knew for sure.