it's been a long time since anything made me feel genuinely happy without simultaneously making me feel sad for another reason

That's a feeling I know very well; sometimes I think it's part and parcel of having a lifetime of hugely varied experience and the intelligence to see consequences.

something would have to come along which would make me so happy that it outweighed the myriad little disappointments it would inevitably cause in other areas

*heh* you'll find her someday :)

It wouldn't help if she lived a long way away, because then you get the disappointment factor.