I've been lurking for a long time and registered to send a message on a this thread, specifically to Coconutter but it may help others.
I was one half of a 'golden couple'. We were destined to be together, people commented on how amazing it was we found each other, we were going the full distance, and we were solid. No children (I never wanted them, he was ambivialent at best - although I think he'd be a terrific father).
Except we weren't a golden couple. We loved each other very much (still do), never argued, there was no abuse or affairs. But we weren't married. There wasn't a marriage there, there was two fantastic housemates and friends. We knew about it, talked periodically, made a few big efforts to sort things out. Nothing changed - we were fantastic at being friends, but not very good at being married. last summer I got home one evening and sat in the car knowing I didn't want to be there. A couple of days after that we talked, a bit, and I said I was going to a friend's for a few days. That was a Wednesday evening, and he was distraught.
The Saturday morning I looked at a flat, having agreed to go 'home' again that afternoon. He rang me (we'd agreed radio silence for the few days) and explained that he'd realised that when I came back, I wasn't coming back to live, but for us to sort out what happens next. I'd started to tear off the plaster if you like, he finished it.
So we split up. I live in a lovely flat near my new part time job, I'm managing to keep up with the PhD I'd started before the split, I have an insane cat and I'm seeing a lovely guy. I helped my ex choose a suit at the weekend, he was trying for us to organise another meal (me, him and my fella - who he knew I liked before I did), I helped revise a speech he's giving next week for work, he bought me a funky hat to say thanks for the suit help. He's paying for the divorce next summer, I'm buying the meal out to celebrate. We're still desparately good friends. It can turn out ok. There have been no regrets about having been married, just a sadness for a while that it didn't suit us. There's no bitterness, anger or hurt.
Sorry - bit of an epic. But I just wanted to tell you my story in the hope it might help. Good luck to you all.