The dominant evolutionary agenda when it comes to human beings is probably not much more than Survival and Reproduction. If you leave the system on auto-pilot, you’ll probably wind up with someone with whom you can do those two basic things: survive. (check.) reproduce. (check).
There’s nothing there about happiness, satisfaction, peace, contentment, meaning, and so on.
Those are real. And yes they do matter. But you’re going to have to take care of those yourself. Evolutionary inertia and momentum have their hands full with just Survival and Reproduction.
Most people probably do not spend anywhere near enough time deeply understanding who their partners are as people in the world. We’re usually more concerned with various expressions of what could be thought of as Fitness. How “Fit” is this person? Fit for childbirth. Fit for building a home. Fit for navigating society. And so on.
Nothing wrong with that. But we need to go further.
Beyond just the fitness of the person, we need to think about the Functions and Purpose of the person.
You won’t find out a person’s purpose by socializing, sexing, or dating. To know a person’s purpose, you have to watch them as they enact that purpose.
But the other half of the equation is that you also need to explore your own.
Eventually, after you’ve fucked and procreated (if that’s your path), and after all the dust settles, it’s probably going to be the combination of your (barely understood) purpose and the other person’s (barely understood) purpose that ends up determining the course and the fate of the relationship.
It’s a lot less interesting than Ass Shapes and Youthful Vigor.
And, in our defense, also much harder to understand.