Has anyone here had a painful breakup, and gotten back together again later for good?

we have been together for 6 months then split. She was just 15 y.o. i was a bit older. About 5 years later we met again. We both changed to more adult people and our feelings were even deeper than before so we married each other but 6 months later it stopped working again, we didn't change the most important things for relationship. I think the time make you more sensible but u still stay the same person as you are now