I like some friends that "fit my vibe" and also like some
   friends that make me go, "Woah, wait a minute, how can you think
   that!?" which forces *me* to question my own thinking on
   matters. After all, they came to their conclusions from
   somewhere as I did from mine. So I have to backtrack and try to
   reconcile. There's always a way to reconcile or very nearly
   always. So if I find someone that consistently 'gets my goat', I
   want them as my friend and I want the challenge of understanding
   their point of view *and* accepting its validity from their
   standpoint. I feel broadened when I do that, as if a whole
   category of thinkers have their ways of thinking exposed and
   open to me and I can say, "Yes, I understand you". without
   following with, "but you're wrong". I can _also_ follow up with,
   "but you're wrong", but I will do so from an understanding
   position. Just as powerfully, this whole process forces me to
   consider the places where I'm wrong, as I go through the process
   of reconciling their ideas with my own. It tempers the knee-jerk
   in me and forces me to listen more closely.