Recently I posed this question to a couple who'd been married 23 years. That's a long time within which to make a mistake or two. The husband had been talking about the wife's extravagant spending habits and how she'd complained about living in Albuquerque. The wife had been going on about how rude the husband was and how he always had to have things his way and make all the decisions. Each insisted the other had been inconsiderate for years.
Solutions usually require people to change.
Each of us has absolute power to change our own behavior and attitudes. None of us has any power to change someone else's. We can influence someone else to change or we can motivate or inspire them. But if they are to make changes, it will be only because they alone wanted to change. So, when husbands and wives focus their time and energy on what the other spouse has done wrong, they are not realistically addressing solutions.