The reason why I brought up this story in the first place is because I place ALOT of emphasis on energy...energy in the same way that you're talkin about...getting to know the person...and do whatever it takes to communicate that I love them as a friend or otherwise. So I definately get WHY INTJ's do it...I just don't get HOW? The huge difference I think is that INTJ's have the ability to "drop" someone down a level or "let go" of a person easier...Maybe what I'm getting at is....
Is it as easy as I think, for INTJ's to do this? or is it like an all or nothing thing...so it's easy?
I personally hate when I put way more energy into someone or even something that I'm doing for someone, and the other person does not even TRY to reciprocate...

and it turns into this endless cycle of: Me putting in too much effort, getting hurt cause the other person doesn't do the same, but then I will do it all over again...as if I did not learn the first time....<---I just wanna know if there's a function I can develop that can help me to STOP doing this. Is it Ni? Cause I repeat history too many times...It's like I have to wait for the person to hurt me to the point of no return....why is an INTJ's "endurance" for this type of stuff different? Do you think it's purely introversion vs. extraversion?