[guesswest]

I'm finding this whole thread a little scary. Picking a partner by measuring her (or him) against qualities x, y and z seems like a very detached and sorta sociopathic means of mate selection. We don't choose who we fall in love with, or at least I don't think people with a decent sense of emotional connectedness and empathy do.

It probably does involve the attributes a person has in relation to your own, but if so it's an unfathomably complex process we couldn't begin to deconstruct, and probably in some way related to the way in which each other's damaged parts fit together as much as it is the objectively positive ones. Setting aside the problems RE the rareness of the person the OP describes - I'm guessing if he found her she'd run a mile upon realising he was pursuing her based on some kind of dehumanising formula.