Summertime is wedding time for thousands of couples. For months, perhaps even a year, you’ve been focused on making your wedding day perfect. Thoughts and conversations have gone into deciding everything from colors for the flowers to what to say in the ceremony.

Hopefully your day really was perfect — or at least as close to your idea of perfection as you could reasonably expect. But after the wedding, after the toasts, the first dance, the party, and the honeymoon, there is this thing called marriage.

Even if you’ve been living together, most couples experience a shift in their relationship. Marriage is not “just a piece of paper” as more than a few young clients of mine have protested. You have made a promise to be together for richer, poorer, sickness and health. You’ve said to your partner and all the people who are important to you that you’re in it for the long haul. Marriage changes us as individuals and as a couple.

Healthy couples do go through some predictable stages:

The first three to six months: The honeymoon stage.

The afterglow of getting married can last for several months. You did it. You got married. For people who are happy with the decision, the celebration lasts for several months. Photos of the big day are posted on Facebook. Relatives and friends who couldn’t get to the wedding still call with congratulations and maybe a gift. You put together the wedding album. Every time you see the shiny new ring, you remember when your true love slipped it on your finger. Sex is frequent and exciting. You experience a new intimacy and a renewed commitment to each other. It’s a sweet time; a time to be treasured.

Six months to a year or so: Reality.

Somewhere in the latter half of the first year, you may start to find out you’re not quite on the same page about mutual decisions and lifestyle as you thought you were. Unmarried, you could put off some issues or pretend they didn’t have an effect on you. But now you may need to revisit some of the issues you avoided talking about.

How will you handle money? Expenses? House cleaning and chores? How about your relationship with in-laws? How often should you visit and for how long?

You may find that your partner (or even you) have different expectations now that you are a married couple than you did when you were merely the boyfriend or girlfriend. Handled with courtesy and respect for each other, discussions about these issues will only help you grow as a person and as a couple. Handled badly, they can lead to disillusionment and perhaps even questioning what you got yourself into.

The couples who thrive are those that work on issues as a team against the problem, rather than as individuals against each other. Being a winner isn’t the point. Winning as a couple is. That means learning how to come to something you both can live with when you disagree. You are laying the foundation for how you will handle the hundreds of decisions, big and small, that will need to be made over the next 40 or so years.

By year three.

As people settle into the next few years of marriage, they adjust and adapt to the reality of being a unit as well as two individuals. The thrill of being together has worn off but the love isn’t worn down. It has just changed into a quieter, simpler dailiness.

This is normal. Married love is different from new love. Sure, there are still moments of excitement. But as you settle into feeling secure and comfortable with each other, your love becomes more mature. Sex may be less frequent but it is no less loving or satisfying. Conversations may be more about logistics than sweet talk. That’s okay as long as you still know how to come out and play now and then. Little but regular gestures of affection keep things warm between you.

When children get added.

Your relationship takes a bit of a back seat to the needs and demands of parenting. Hopefully, your shared pleasure in those children offsets the loss of time just for two that went before. Hopefully, you’ve made a commitment to carve out some couple time on a regular basis to remind each other that you are lovers as well as partners in getting through the days. Hopefully, you’ve developed the tools to be a team as you juggle parenting, jobs, finances and household tasks. If not, you may break apart. Couples who become even stronger are those who delight in the expansion of their role into caring for children while still caring about and for each other.

Mature marriage.

Once you figure out how to be parents and partners, you settle in to who you are as a person and come to terms with how you’ve defined your marriage. You’ve built a shared history of experiences, memories, and successes. You’ve come through some tough times. If one of your children had a lengthy illness or a rough adolescence and you all got through it, you may celebrate your collective relief as well as your collective growth from the experience.

You have a right to be proud of making it through that storm and others that came your way. As the kids gain their independence, you have room to re-appreciate each other and to find each other as “partners first” again.

For many people, the emptying of the nest or the pending conclusion of career ambitions allows for renewed but more mature romance. You’ve accepted each other’s differences and still love who you love.

Not all marriages go through these stages at the same rate or in the same time frame. Couples who try to do more than one stage at the same time (say, honeymooning with a new baby or making a second marriage work while parenting teens) find the process particularly challenging. But it’s important to understand that shifts and changes in our relationships don’t mean that there is necessarily something wrong.

Change is part of life. Couples who celebrate their 50th or more anniversary are those who learn how to embrace change, working as a team to accommodate when it’s right, and altering the course together when it’s wrong.