Hmm.. Well, keeping in mind we were all born single. And without a stitch of an outfit as well.

BRRR!
(Except for twins or triplets of course.

)
So that was the original state of affairs. Getting hooked up with a main squeeze of some sort, was a variation from the status quo.
Based on the existing divorce rates and court cases, I'm not entirely sure we were meant to be paired off, 2-by-2, the way society tells us we should always be. Were we?
Or maybe its just that we aren't careful enough about the decisions we make, or we let short-term passion (read that as intimate infatuation), be our guide? Or perhaps we don't realize in advance the substantial compromise that good relationships really do require of us. Which is good compromise, (hopefully), but nonetheless necessary.
However, since I'm no lady, I'd better not answer this one.
-RB