I was nineteen years old when he proposed and this week we celebrated our 19th wedding anniversary.

We’ve been married long enough that if you were born around the time of our wedding, you’re now in college.

In other words, we’ve been married a lifetime.

And yet, it feels like we are still at the beginning.

We’re still green enough to get that giddy-in-love feeling, but we’re far enough in to understand the power of choice and commitment.

While we were on vacation in June we met a couple on their honeymoon. I told them the first year of marriage was the hardest for me. Despite how it may sound, I was actually trying to encourage them.

I wanted to give them the benefit of something I realized only in hindsight—I made the first year of marriage hard. I started, and escalated, arguments as a way to test my husband’s love and commitment. I was insecure about my own self-worth. I worried he would wake up one day and realize he’d made a terrible mistake choosing me. That insecurity made me not-so-much-fun to live with.

Marriage wasn’t the problem, I was.

We’ve been happily married for almost two decades and I’m still amazed we made it through the first year.

In our 19-years of marriage, we’ve learned there is one key to unlocking and maintaining happiness in marriage. Truly, one key. The best advice about how to have a strong marriage comes back to this one key:

Marriage is a choice. Choose each other each day.

I remember the moment this reality dawned on me. Somewhere along year seven. Neither of us had “the seven-year itch,” but year seven was THE year our world changed.

We had been so focused on building a family through pregnancy that when it became clear it wouldn’t happen, we had to re-group and ask the question: “If we can’t have a baby do we still want to be married?” When the question finally came out and we could each definitively answer “YES!” it was the best kind of vow renewal.

Somehow the commitment of that moment was even more profound to me than our wedding vows.

When we chose each other during a tough time, our already strong bond became unbreakable.

Each day we get to choose each other all over again.

Sometimes we mess up and we choose the wrong thing. We choose our work, our friends, or even serving in our church instead of focusing on each other. Other times we let emotion get in our way. Without meaning to, we choose anger, disappointment, fear, or even guilt instead of each other.

The thing is, we don’t make the wrong choice on purpose. We make subtle decisions that keep us from our deepest connections.

We don’t intentionally choose Candy Crush and Twitter over meaningful conversation with each other, it just happens. The kids are tucked in and we plant ourselves somewhere for a few minutes without having to answer any questions, make any decisions, or explain anything. Two hours later, the entire evening is gone.

If that happens once or twice, it’s manageable. If it happens over and over again, our marriage weakens because our sense of connection to each other is strained.

We can get locked in a season of conflict or discontent, but now we know we have the key. When things feel out of whack, we put the distractions aside and choose time with each other.

Are you married? Do you and your spouse choose each other over and over again? If not, what gets in your way? Tell me about it on Facebook or Twitter or send me an e-mail.