My story is this: had my DC young (too young), thought I'd screwed my chances, was in a marriage that went from bad to worse.
Fast forward 10 years: I left XH, devoted myself to trying to do the best I could for my DC, tried to recapture a bit of my career, intellect and prospects (not very effectively, because everything had to hinge around being a single mum and doing what best I could. No support from XH)
Fast forward 20 years: I was driving to work the other day, the sun was in the sky and I suddenly thought "hey!, I have totally made it! I am now married to a DH I love, who loves me, my DC are OK, more than OK, both at uni doing really well, I have a great job I enjoy and that gives something back, and I have colleagues who are friends, and family who are there for me", For me, that is an exceptional result. And the amazing thing is, the more it goes well, the better it goes IYSWIM. Because I got into work, and during the day, I met someone who said "Oh, I've been hoping to meet you, because I wanted to offer you this X job". And it was the job of my dreams.
The exceptional can come to you. But you have to put in lots of time and effort and maybe even grief before you get there. But now, I'm 48 and yes, my life's exceptional, not mediocre. You can get there. 20 years might seem like a long time, but trust me, it isn't.