How do we define love?

I was randomly thinking about something today, and when it occurred to me, I wondered how I had never considered this idea in the past.

Why are we as people constantly searching for an eternal lover?
You know, that person we hope to one day find, marry, and be in love with forever?

I had always looked at this notion as the norm, hoping to one day find someone like that, start a family, the usual.

But if this concept is dependable, then why are more marriages ending in divorce rather than in adjacent tombstones? Are we striving for an ideal that is almost impossible to achieve? And yes, I know there are couples that have been together for a majority of their lives and can still be happy, but for most of us? Unheard of.

So why do we still strive to find just one ever-lasting love? What if we lived under the mentality that there isn't just one person for us out there? What if the goal was instead to just be happy, and to find love when you can, even if that means beginning the cycle again and again? Maybe we're too stuck on the idea of a soulmate/husband/wife, that we no longer can appreciate or feel comfortable having a multitude of serious lovers indefinitely. I think we are searching for stability, but shouldn't we be able to find that stability within ourselves to not need another person, but still be able to welcome their presence when/if they arrive?

And then I wonder about the way our society structures families. If people didn't marry, but just remained involved in a relationship until it soured, but still had children, then the concept of "family" would alter a bit, too. Though, nowadays most families are like this anyway. But it's interesting that society puts so much focus on the idea of a "family." What if it meant something different? Something less bonded to a small group of blood relatives, but more connected to everyone around you. I'm not sure if this part makes sense. I didn't really think about the family aspect until just now. It's weird to me because I'd barely questioned either of these things. It makes me wonder what other societal traditions I've solidified as "the norm" in my mind, but that don't necessarily need to be considered normal.