1) How does this work?.... Ah, so that's it! Now, how do I fix it?
2) Why is that in there, and what's it for? Why is that so important?
same here. I wonder if my coworkers get tired of my incessant questioning...
I work at an auto repair shop as asst. manager, so the knowing the theory of how the individual parts make the car function is very interesting to me. Hell, thats probably the thing that interests me the most about anything: how the individual parts work together in the collective. Diagnosing problems are fun

But does that mean I want to implement my solution and actually work on the car? Yes and no.
Hm. I'm glad I responded to this thread, given I've been really undecided as to what career path I want to go through. This has helped me figure out what I like to do most and what would satisfy and motivate me the most: implementing my theories as thoroughly as I possibly can. Now I can see why some INTP descriptions talk about our impending fear of failure...because in regards to certain things, our abstraction or conception isn't complete and thorough to our satisfaction where we're confident enough to implement whatever we've conjured up. I'm sure nothing is more distressing and unfulfilling than a failed/fractured/incomplete theory/abstraction but even then, thats ok. there's still plenty of time for more learning, or at least we can hope.
Honestly makes me wonder why we see life through this lens. Although we might have our distinct traits we've acquired from environment and conditioning, we still have our underlying similarities, just like all the other types do. Not to say the MBTI is some rigid thing that we must abide by, but its a pretty good conjecture. What a man Carl Jung was...I need to continue reading his book, the psychological types.