I'm going to try to make a series of short(ish) takes on why relationships fail, based on what I've learned from my own failures in my own marriage. To start us off I want to talk about Keeping Score.
Relationships aren't about who is more right or more wrong, it's about working together, and trying to become better people. Keeping 'score' counteracts all of this. See, the problem with being humans is that we will spend our entire lives hurting other people and trying to find ways to apologize. We are not perfect, and we never can be, and so we will always hurt other people, even when we don't mean to. Keeping score of who messes up the most in a relationship is a one-way ticket to a break up.
So let's break this problem down-
What does it mean to keep score? Keeping score means tracking how many times your partner has messed up, hurt you, or been wrong, then calculating how much good you've done, how much you've suffered through and comparing those things. It could be as practical as, "Well I've washed the dishes six times, and you've only washed them once."
Why does it hurt to keep score? Keeping score hurts a relationship because it breaks down life into what are now considered 'wins' and 'losses' each time I do dishes I win, which means you lose. Each time you make me feel bad you lose, and I win. That's not how life is. Life is a constant cycle of seeing a small ugly truth of who we are, and then trying to do better. Keep score removes accountability and responsibility. It means that we are not holding ourselves accountable for our own short comings, nor taking responsibility for our failures. It also means that we are telling our partners that they will never grow, they will never do better, and that we will always find some way that they 'lost'. It pits each partner against each other, and makes relationships a battle.
How does it hurt to keep score? It hurts because it means you're holding the other person to an old standard and refusing to let them grow. It stunts the relationship, makes it antagonistic and drives you apart.
Disclaimer: There is a difference between acceptable mistakes and abuse or the breaking of fundamental trust and values. This advice is only for acceptable mistakes and how to be happier with the person you love, who loves you, it is not a way to justify abuse or forgive actions that are well outside the boundaries of what we find forgivable (cheating, for example).
What should we do instead? There's two solutions that I see,
1. Figure out what's going on. Most times we don't want to hurt each other, we don't want to be cruel, it just happens, because we're imperfect. When there's a behavior that's concerning or hurtful (not enough physical touch, always on the phone, doesn't listen, talks over you, etc...) chances are that person isn't meaning harm, and they probably don't realize what they're doing. Having a quick check in, "This is how I'm feeling because of this action/sentence. Can we talk about that?" is a great start. It keeps the blame out of the conversation and instead focuses on how everyone is feeling and the practical actions that led to that. Each person is allowed to see the other side and empathize, and sometimes you'll even make a discovery that helps in the future. I can say, "oh, his depression is flaring up so he's not being as physical/is stuck to his phone/doesn't want to go outside." He can say, "oh, she needs physical contact to know that I love her, I didn't know that before, now I know how she communicates." We've all listened to each other, and we have possible solutions going forward and know more about each other, and more about how to take care of each other.
2. Forgive and forget. You can't hold onto things that go wrong in a relationship. You just can't. If you do then you'll never be happy. Do you keep tabs on every single thing you do wrong? Does that make you happy? Do you want to do that to yourself? No. So don't do it to someone else. Especially because holding on like that can mean you don't talk about your concerns/problems and so they never get fixed so they will get worse and the other person will never know. No one is a mind reader. Do not expect anyone to be. Each instance of a problem is separate. The first time I talk over my partner, he'll correct me. If I do it again we'll have a bigger conversation about it. If I keep doing it then we need to either talk to someone else together, or we need to figure out what needs to change. Sometimes it takes time for things to stick, if we can't genuinely forgive each other for every mistake, and not keep a tally of mistakes, we'll never live in the love and compassion we need to have long term relationships with each other.
Relationships are hard, and there are things we all do that makes them more difficult, there are ways we are as humans that make them more difficult. Hopefully with a little awareness and thought we can avoid this pitfalls. Pitfalls found not just in romance, but in friendship and family, as well.