My brother-in-law is getting married this week, and of course I wish him and his fiancée all the happiness in the world.

They're both in that lovey-dovey phase where their Instagram posts are all very mushy, so things are off to a good start.

Weddings tend to get me thinking about what would be the most helpful advice I could offer.

My brother-in-law hasn't asked me for any (and I don't volunteer on my own), but I wanted to be prepared just in case.

So what's the one piece of marriage advice I'd offer?

If I had to choose just one thing, it'd be this:

Do your best to remember that a marriage is something you and your partner are always guiding together.

It's like riding a two-person canoe.

You're both in it together and headed in the same direction.

Sometimes one of you is paddling harder, and sometimes it's the other one.

And wherever you go, you're going there together.

In the beginning, it feels natural to choose a direction together.

You've only got eyes for each other, so paying attention to each other is easy.

But life slowly complicates this.

Health, careers, kids, family, and money are just a few of the things that will jostle your canoe.

You won't always agree on where to go.

And there'll be times your partner doesn't seem to be paddling hard enough.

This is going to happen because it happens to everyone.

My brother-in-law probably can't picture this yet.

Newlyweds have a hard time imagining how far off-balance a marriage can feel.

I know I did.

But if you've been married for a while, you've probably already felt it.

And maybe you're feeling it right now.

Where it seems like you and your husband want completely different things.

Or it feels like you're the only one still paddling.

Here's what I'd want you to know:

What you're feeling is the exact thing I'd warn a newlywed about.

This isn't a sign that your marriage is lost.

And it doesn't make you the bad guy. Or your husband.

Life is such a wild ride that we all lose our sense of direction sometimes.

And the more you fight each other to take the lead, the more stuck you'll become.

When you can see it that way, the answer becomes clear.

The only way to move forward is to move together.

My wife and I have had our share of times feeling stuck, like when we couldn't agree on where to start a family, or the right school for our daughter.

Both times we thought we were fighting each other.

And things only changed when we remembered that we were on the same team.

That it was really the two of us against everything life was throwing at us.

It sounds like an easy thing to remember, but it's not.

Because life distracts us from that truth.

The only time you'll feel like you're getting somewhere is when you and your husband remember you're paddling together.

And that's what I'll tell my brother-in-law (if he asks).