For some reason, we think that in order for our marriage to be successful we need to solve every problem. Every detail needs to discussed and couples just have to see eye to eye on everything.

Thankfully, this is not what successful marriages need. According to relationship researchers Julie and John Gottman, "an astounding 69 percent of relationship problems are perpetual. These problems don't have a solution and are therefore not going to get 'fixed'."

Here are three problems that happen in every marriage that actually shouldn't be fixed.

1. Toilet paper problems (and other issues)

Under or over ... the age-old question. You have one preference and your spouse has the other. But when living with someone, it's important to remember that there's no "right" way, just preferences.

So what does this mean for your marriage? Basically, don't sweat the small stuff. There are many things that you are going to disagree on. Instead of fighting about things like toilet paper or where the milk goes in the fridge, choose to let it go.

You and your spouse will be happier if you both learn to tolerate (or better yet, embrace) each other's preferences.

2. Money

Money is a tricky one. You do need money to function and not being in debt is one of the best things for a marriage. However, the stark difference in how money should be saved, spent and budgeted means money problems are a part of every marriage.

We often find ourselves judging others on how they spend their money, especially in a marriage because how your spouse spends money affects what you can spend money on. Instead of constantly battling out who gets to buy what, make a budget together.

Decide what your priorities are together, and how much money you both want to save each month. Be sure that the budget includes money for each partner to spend however they want.

Remember that there isn't a right or wrong way to spend money but a good, better, best. Money will always be a part of your marriage so choose to work towards compromise instead of obsessing over a solution.

3. In-laws

You love your spouse but you may not love their family. This can be a tricky thing because most likely your spouse loves his family. Consequently, you might find yourself fighting about who to spend time with this holiday season.

In-laws are a source of stress and problems for many couples. But again, it's one of those perpetual issues your marriage will never be without. In order to keep the in-laws less of a problem, you might need to keep your opinions to yourself.

Yes, being with in-laws can be hard, but that is no reason for you to tell your husband that you hate his family. When you tell your spouse that they may take it personally and it will lead to other problems. Sometimes it's better to just keep an opinion to yourself to protect your loved one from hurt feelings.

As much as you can, try letting it go and moving forward. If it comes to a point where you can't sweep your hurt feelings under the rug, it's time to discuss the issue. Maybe you need more time with your own family instead of so much time with the in-laws. Maybe understanding your spouse's family will help you understand why they act the way you do.

Problems happen, but learning to work together despite your differences is what marriage is all about.