On a recent Saturday morning, coincidentally my 17th wedding anniversary, I was flipping through the channels on TV and stumbled on a documentary, 112 Weddings, created by filmmaker and wedding photographer, Doug Block. He was following up with some of the couples whose weddings he photographed years earlier to see how they were faring. Did the marriage meet their expectations? Are they happy? What kinds of problems had they encountered? What would they tell a couple who was embarking on the marital journey?

I found it fascinating. The couples, all New Yorkers, were candid and forthright. Some were still happy, some were divorced. But universally, they didn’t see the institution of marriage through rose-colored glasses. They had all been married long enough to know that trials arise. How you feel on your wedding day is not how you will feel every day. Marriage, even at its best, can be a messy business.

The film got me thinking about my own views of marriage. About what I would tell that young, fresh, 24-year-old couple. If you had asked me at the time, I would have thought that I was realistic about marriage. My own parents, still together today after over 40 years, had their ups and downs. I didn’t have a Hollywood, romanticized view of marriage. Still, the reality is that, like life, marriages are dynamic. Since none of us can see into the future, we can’t really know what we’re signing on for because we don’t know what life has in store; we don’t know what curve balls we’ll be thrown or when.

In short, we don’t know the ways in which we’ll be tested.

And this is where I think my naïvete kicked in. Sure, at some abstract level I knew that we would have “challenges” but somewhere in my youthful and inexperienced mind, I envisioned disagreements that would be resolved through a level-headed process of give-and-take. In my narrative, we were two mature, rational people with good heads on our shoulders. We’d been dating almost 8 years (we met in high school and dated throughout college) and had lived together for a year. We had already merged finances, decorated an apartment and ironed out issues like household chores and personal space. What else was there?

At some level, spoken or not, I think I believed that when we were “tested” individually or as a couple, the answer would be clear. We would simply stay the course, stand by each other, compromise . We would “turn towards each other” (as they say in all the books on communication) and not “away from each other,” and methodically work through any problems until the storm–or the test–blew over.

Spoken like someone who has never been truly tested.

When a real test presents itself, it is characterized–indeed defined (at least in part)–by the absence of a clear course of action. Ambiguity reigns. The stakes are high and passion on both sides becomes a breeding ground for misunderstanding and conflict. These are the moments when there is no clear path. A true test feels less like an inconvenience than an assault. Turning towards each other doesn’t feel so easy. In fact, under the duress of a true test, you aren’t even sure what that means.

I think that in the minds of many people, the hallmark of a good marriage is the absence of crisis; the avoidance of tests. Indeed lots of people actively eschew conflict because they don’t like the messiness and the uncertainty of tests (no one does, some just try harder to dodge it).

But the older I get and the longer I’m married, the more I see the holes in this approach. After all, if there is no struggle, there is no growth. If you live long enough–or are married long enough–life will eventually hand you something that you don’t want. You’ll be faced with a choice: Assimilate and integrate in order to move forward; or don’t, and likely end the marriage. In other words, it’s not about meeting in the middle, it’s about growing together, though probably not in exactly the same ways. It’s about accepting that sometimes you encounter something so profound that the world doesn’t look the same afterwards.

The strongest marriages, I’ve come to realize, are the ones that don’t duck this growth. It might be painful–is there any other way to learn hard lessons?–and it might highlight differences in how you and your spouse see the world. You might realize, perhaps for the first time, that you have differences that can’t be reconciled through a process of give-and-take, but that can–with work–be allowed to coexist.

One of the hardest life lessons we all face is that reality often doesn’t meet our expectations, and at no time is this more apparent than when you are faced with a test. You expected to both be healthy and vibrant well into your 80s; one of you becomes disabled or ill. You expected financial security; you live paycheck to paycheck. You expected to be on the same page in terms of where to live or how to raise children; you’re not. Often we hear from well-meaning friends that we “deserve” better than what we got or that we “didn’t sign on” for whatever it is we’re dealing with. But what does that really mean? What do we really deserve in our relationships or in our lives? Only what we’re willing to work for, and even then, we never have any guarantees.

Except this one: If you’re married long enough, you will eventually fall short of your spouse’s expectations and they of yours in one way or another. This is the real test. Do we stay together or do we leave in the hope that the next man (or woman) will meet the expectations our current partner does not? What if, in turning towards our partner, we are turning away from something–or someone–even better?

Which brings to what my 24-year-old self didn’t know when she walked down the aisle. That the true tests wouldn’t just force me to confront my partner and his perceived inadequacies, they would force me to confront my own shortcomings and assumptions. In other words, sooner or later, I’d have to challenge my expectations and my sense of entitlement. I would learn that “turning toward my partner” really meant turning toward myself and facing up to the fact that life and people don’t always do what I want them to do.

And isn’t that the great test of life? Bridging that chasm between what we think we deserve and what we actually get and navigating all of the difficult choices that go with it?

Many young people enter into marriage so that they can share a life with someone, build a family. And certainly that’s a big part of it. But what you’re doing underneath all of that is learning about yourself. Growing and changing, and learning to do this with another person. Tests, marital or personal, are usually looked upon as a very difficult time. But if the relationship emerges from it intact–and not all do–the couple knows they are made of tough stuff, personally and together.

And when you know that, the next test–and there will always be another–feels a lot easier, and a lot less scary.