No relationship is perfect, because none of us is perfect. Hell, my relationship with myself isn’t perfect, but for obvious reasons I can’t get up and leave that one.
I know I’ve shared this before, but this is too great a setup to not tell it again:
My dad is a mathematician by training. He’s also polyamorous and in a group marriage. He once told me, “The ideal number of people in any relationship is 0.6…after that, it gets complicated.” 
Oh I don’t doubt legitimately happy people exist. The flaw in your theory is that a person’s happiness should be the primary measure by which we judge someone. Plenty of “happy” people are happy narcissistic sociopaths. Or idiots. Or simply jerks.
And how do you know if someone is “legitimately happy” or if they have just become good at putting on a facade? Being upbeat and positive all the time is a hallmark of con artists, cult leaders and sales people.
Yes, but perhaps you have a 90% chance at meh and a 5% chance at deliriously happy. Even with those odds, many people, probably most people in the Western world, feel the same way you do. But some don’t.
Reading this thread, I keep thinking of my brother and my sister in law when they had their rough years. I wish I had a good check list or formula showing why they stayed together, but all I know is that they loved each other and were committed to making it work. They also knew things would get better. I’m sure that was part of it.
What happened to cause the rough years is that my brother went to medical school in his mid 30’s. At the same time, they wanted to start a family. They knew it would be a tough time commitment and that they wouldn’t see each other much. They both agreed they were up to it. But actually going through it was much, much tougher emotionally than they imagined.
My brother had to compete with people 10 or more years younger than he was who could work on less sleep, had just finished undergrad (which for my brother was 10 years earlier and things had changed), and didn’t have family or the same financial commitments. He’s always been at the top of his class before, and now he was struggling to keep up. He was tired, feeling insecure, and terrified of failing himself and his family.
My sister in law was a new, young, stay at home mother who was alone most of the time. She was terrified that she was doing everything wrong, and friends (often childless) didn’t think twice about telling her she was, in fact, doing everything wrong.
When they did see each other, they were both exhausted and both needed the other to boost their self esteem.
So they’d have days like this one after the baby kept them both up all night…
My brother had a horrible day where he performed less than acceptably, felt like a complete failure, and just wanted to get home and have a nice, relaxing meal. The whole drive home he thought about how maybe he wasn’t really as smart as he’d thought he was, maybe he couldn’t do this medical school thing, but at least he had a family who loved him and would welcome him.
Meanwhile, my sister in law had been preparing dinner only to find the baby had put pennies up his nose and they were stuck. Several frantic phone calls later, she managed to unstick the pennies, all the while feeling like a failure for turning her back on the baby long enough for him to get penny nose. When she returned to the kitchen, she found the dog had gotten into dinner preparations, eaten them all, and then yakked them up all over the carpet. All she wanted was for her husband to hug her and tell her she wasn’t a bad mom.
Of course, my brother managed to walk through the door just as my sister in law had finished cleaning up dog yak. It was the worst possible time. Feeling neglected because no one (except the bad dog) noticed him coming home, he rather curtly asked what was for dinner… and my sister in law sat down in the middle of the kitchen floor and started sobbing.
They laugh about it now. It’s one of the family stories that comes up periodically (to the great embarrassment of my nephew, he of the penny nose). They have a wonderful, very happy marriage now. But those years were hard for both of them.
I think I remember your sharing that before, but it’s still a great line.