For us, I'm 13 years younger than DH. When he was my age (when we met) he wasn't mature enough to be in a relationship. He was married prior, no children and they divorced amicably mostly because he was selfish with his time and didn't fully understand that he can't do whatever he wants when he's attached and has responsibilities. He matured, sowed his oats, advanced his career, found me and we've been married 17 years.