If we were relations of identity, I think we would have been constantly congratulating each other on how wonderful the other was, because we approached things all the same way.
Instead we had all of this stuff to talk about and almost never run out of things to talk about, had a very companionable vibe, but our approaches to things kind of confused or annoyed each other.
I remember there was also this sense of both of us thinking that the other one thought he or she was better than the other one. "You think you're smarter than me," he would say. Or he'd get mad at me and say I was meaner to him than anyone. One of our last big fights before we didn't speak for six months, I felt like he was making fun of me (he was) so I started making fun of him and he was like "OH NO THIS IS WHAT YOU REALLY THINK YOU CAN'T TAKE IT BACK."
Meanwhile, I always felt like he thought he was better than me, like he was more sophisticated, or more "together" (he's very much the tidy, under-wraps ISFj) or had better taste in music or something, and he'd always just kind of casually troll me and mock me.
It was very much the epitome of my area of confidence being his creativity and vice versa, leading to mutual admiration and even helping each other, but also to a sense of approaching things differently and disagreeing, or even feeling inferior to the other in some area.