GasP agree with a lot you've said.
I thought I had a "normal" relationship (20yrs) but as I get older and see what happens elsewhere - and some of the horror stories on MN! - I realise I've got it pretty good.
We laugh. We chat. We find each other attractive. We're on the same page with our outlooks (there's things we differ on, but on the big ticket items we're similar). We support each other - we've gone through different stages of who has been the main earner, who has not worked at all etc but we've always thought of these as joint situations. He's a hands on dad. He irons his own clothes. We share house stuff - sometimes I'll do more or he'll do more depending on what else we've got on. There's no jealousy. No fear. No tension. No resentment. And most of all, I've never found our relationship hard work, or so something that has had to be worked on. It's just a natural way of being.
But even after seeing the shite that goes on elsewhere, I still don't feel like I've won some kind of relationship lottery. I think that what I have is just what it should be for everyone.
Thinking back to when I was a child, my parents had a good relationship but there were times I knew others were not "right". I remember my friend telling me her dad wouldn't allow her mum to learn to drive. I must have only been about 8 but some kind of alarm bell went off. I also remember hearing my mum and her friend discussing the friend's husband (prison, violence etc) and the resigned "well what else is there?" tone of the conversation. I think at some basic level, seeing and hearing those kind of things set off some kind of defence mechanism in me. I never had a particular ambition as a child, but I knew that I had a good brain and getting an education would give me options beyond what I was born into. I've always been adamant that I can support myself.
I've had a fair bit of luck in that my children are NT and my husband and I are both in good health and I appreciate just what a difference that makes to your options. But I do strongly believe that if any one particular thing has "saved" me from rotten relationships, it's that I've always believed I'm entitled to a good one and that I'm capable of going it alone rather than being grateful for what I receive.
I'm reading this back and it's very me me me and stinks of smug and I promise you, I'm the least smug person out there, but I hope it's useful to someone maybe wondering if they're just not trying hard enough, or if their relationship would be better if they just changed xyz about themselves and they can maybe stop being so hard on themselves. Hopefully it's come across the way it is intended rather than "I'm so great and you're all doing it wrong" 