So I guess here's my main question: Let's say you break up with someone because you both misunderstand and dislike each other so much that you can't be together. Would you talk things out so you could understand why they are the way they are instead of just thinking they're a jerk? Or would you not talk about anything because you just don't want to face the pain?
And say you both still want to try to be friends. Would you work out your differences so you can avoid future misunderstandings? Or would you not talk about it and leave it behind so you wouldn't have to go through that painful process with them?
I find it impossible to just leave such a painful situation behind. I have to understand what happened or else it just keeps coming up over and over again. I can't not talk to someone about something big and pretend that everything's okay between us. Every time I see that person the bad feelings from that situation come up.
Do you think the only way she could heal was by never facing the situation again? Do you think she had a valid point or do you think she was just avoidant? If she does, how can I deal with someone like that in the future?
Random Ness, I'm still catching up on this thread so I haven't read everything yet but let me take a stab at this...
I don't think Fi (used by INFPs and ENFPs) is inherently avoidant. I'd say it's cautious about revealing itself. And, after it has revealed itself, it makes the Fi user feel a bit drained and emotionally exposed. At least that's how it feels to me. So, no, I don't think Fi would be the driver in your INFP ex's avoidant behavior.
This may simply be a case of her protecting her heart. Even if breaking up was the right thing to do, such events are always the source of a lot of heart ache and self-evaluation. Fi would indeed be a big player in this process for any Fi user. And as Fi is wont to do, it will usually play a private, not publicly articulated role. In other words, Fi would want to understand, but not necessarily discuss with another person, its internal machinations.
I think INFPs and ENFPs might handle this kind of thing a little differently. I think it may have to do with the differences between having a perceiving function dominate (ENFPs have dominant Ne) and a judging function dominate (INFPs have dominate Fi). As an ENFP I always want to take in new information and understand EVERYTHING in my life. (And, as an INFJ you share this strong desire to process the meaning of everything because we both have dominant intuition.)
But, I've noticed that there is a subtle difference in emphasis with my INFP BFF. She has Ne as her auxiliary function so she loves to take in new information, too. But her starting point is her Fi... or her vision of <insert situation here>. I've noticed that if her vision for the way things ought to be doesn't match up with the way things really are, she needs time alone to process this. And, me pushing her to process it with me does nothing but stress her out. So my gut feeling is that ENFPs would be more likely to go down the post mortem discussion path with you than INFPs.
So back to your question, maybe your INFP needs alone time to process it and doesn't fully understand the mental forces compelling her to want to run away every time you try to have a relationship post mortem discussion with her.
As far as how to handle this in the future if such a situation arises again... Well, I'd say that you need to recognize that her Fi needs time to grieve over the death of its vision. And, that during this grieving period, relationship post mortem discussions are probably not going to be met with enthusiasm. Perhaps instead of trying to hash out what happened in the past, you can focus on the present and the future. In other words, if you work on just being a good friend to her, then you can handle problems as they arise within the new parameters of your friendship.
I don't think there's a MBTI magic bullet here.