It’s amazing marriages last as long as they do. Especially for those who have kids.

When you first get married, you commit to living with another person and growing with them as you both advance through life. You assume (or hope) that given the foundational elements of your personality and interests, you will grow in relatively the same direction and evolve, together, in a way that may change you both, but not so much that you grow apart.

That lasts for a bit, but then you have children. Children fundamentally alter the relationship as they take your attention away from each other and place it firmly on the kids. Sure, you find times now and again to get away and spend some time alone. And you’re always connecting when it comes to raising the kids and the decision-making that comes along with it. But it’s a connection based on a circumstance that will change again in around 20 years, when they leave the house.

When the kids gain independence, you’re back to focusing on each other again. And who knows where your mind has been the past 20 years and who your personality and beliefs have changed as a result.

Now, after a 20-year sabbatical, you’re back together. In that time, you’ve both grown and evolved, but who knows if it was anywhere near the same direction. What are the chances you both mentally moved along the same path, maintaining the core elements of your beliefs and personality.

And if you did, you’re about to experience another 20-30 years of growth and change, together again.

We know very little about marriage because none of us, whether we’re married or not, get to truly witness another marriage to compare notes. Amazing that we live in a society in which so many people are engaged in the same relationship arrangement, yet we know so little about a typical arrangement and the thoughts and emotions that accompany it.

Marriage is a fascinating thing, and I’m impressed by anyone who keeps it together in a happy and productive way through all of that.