I have a friend who I didn't develop feelings for until much (like 10 years) later, and I think the quality of the relationship is FAR better than the duals who I've been wildly attracted to from the beginning. Sometimes I wish I could just shut off my hormones because they really screw things up. There's a mutual friendship, openness, and respect, with no anxiety, mistrust, or clinginess whatsoever. It felt like we were on the same level in pretty much every way. After my ex, you have no idea how amazing that feels. I guess it would be characterized by one day waking up and realizing you're in love with your best friend, while being completely clueless of it up to that point. Hm, now that I think about it I guess it could be the type of relationship that is truly healing for both parties.
But it still didn't become a relationship, for a number of other issues. And now he's dating some chick he met on the internet. (Fuck you e-harmony for messing with the perfection of duality! *shakes fist* lol)
So yeah, I know what you're talking about.