I have no regrets. Part of the reason (although there were many others) we split up was because I realised he was going to be an student for the next decade, not get married or have children until after that, and probably live in his hometown forever.
What happened was he got together with his now wife shortly after we split, lived with his parents whilst doing an MA and then a PhD and then just married her now after 15 years. So he basically carried on with exactly the same routine for 15 years after we split.
Maybe that's what she wanted to, I don't know anything about her but I did not want to wait until my mid-30s for my OH to complete his studies and get married or have kids.
Thinking about it and factoring in fertility issues, I would have probably ended up sacrificing the thing I always wanted the most, becoming a mother, if I'd waited around for him.
And he would never just SAY what his plans were, he would um and ah and say he wasn't sure what he was going to do and I just had to hang around and hope we were moving in the same direction. I feel exhausted just thinking about what a drain that relationship was, my Mum said to me it was like watching me pushing a monolith up a hill because he dragged his feet over everything.