When I was in high school, I took an extremely interesting marriage and family relations class. We had a section on conflict and why marriages end in divorce ... and it was fascinating.

We talked about how lack of communication was detrimental, money problems were almost always a factor, intimate life was often an issue and how stress-related problems put a huge burden on couples.

I remember wondering why there were so many reasons marriages fell apart, and why we still can't fix these problems. We know why marriages aren't working, so why haven't we found a solution? After pondering this for quite some time, I stumbled across an article that answered all of my questions and made so much sense.

The real relationship killer isn't money. It's not lack of communication. And it doesn't come from intimate problems.

All of these issues are terrible and you should work through them, but they stem from one big problem that silently digs its claws into happy couples - the biggest relationship killer is unmet expectations.

Here's an example

A husband is on his way home from work, and it has been a long day. He's tired and wants to relax for a little while before he interacts with his wife and kids. On his drive home, he imagines walking in the door, giving his wife a kiss then closing his eyes for a minute to unwind. This is his expectation.

His wife is waiting at home, but she has also had long day taking care of the kids. If she hears one more complaint from a child she's going to lose it. She imagines her husband coming home, taking her into his arms then talking with her for the rest of the evening, while simultaneously taking over all parenting duties. After all, she hasn't had an adult conversation all day. This is her expectation.

He wants time to unwind alone, and she wants to chat all night - and this makes for unmet expectations on both ends. In this case, the unmet expectations can portray themselves as lack of communication, lack of caring on both ends and hurt feelings.

The perfect equation

This is just one example, but there are so many ways unmet expectations can take a toll on your relationship. Derek Harvey, the author of the article mentioned earlier, talks about the perfect equation for this problem: Expectation - Observation = Frustration.

People get frustrated when their expectations aren't met, but they don't have to. If you can let go of those expectations and "go with the flow" as Harvey suggests, your marriage will be much happier.

Of course you shouldn't let go of the basic needs you both have. You should expect love from your spouse. You should expect their support. And you should definitely expect to feel safe in their presence.

Let life happen

But when you expect dinner on the table the minute you walk in the door every night, you'll never be happy. Your spouse will always fall short, because nobody's perfect. You can be truly happy in your marriage when you let go of your expectations and embrace what's going on in the moment.

Life is all about imperfect moments, and you should let those moments happen. When you do this, you'll be able to fully enjoy your life and your marriage.