Some of us have the very great good fortune to fall in love for the first time, marry, and live (more or less) happily thereafter.
Many of us (most of us, I suspect) are not so lucky.
No, we crawl off into a corner to pout and lick our wounds.
And then (assuming no real abuse was involved) with time we do manage to heal and go out to meet other loves and try again. And sometimes, then, with luck and perseverance we do manage to find that happily-thereafter person.
It seems to me that we can then spend the rest of our lives feeling angry, hurt, and resentful that that first lover wasn't everything that we needed her to be.