My dad was very poor, when my mom married him. His parents died at young age (40s), left 2 girls and 4 boys. My dad was the oldest boy in the family. He got good education in accounting and started working in publishing industry since age 18. My dad raised all his brothers and sisters, sent them to school. Every month he only left a few yuans to himself for food, gave the rest to his sister, who managed the whole family expenses.
My mom is from a big family, but her dad was a businessman. She did not have to worry about money, when she was child.
My dad was 33 when he married my mom. His youngest brother was just finishing up the school. My mom told me that she married my dad, because she knew he had a good job, was smart and good hearted. He raised his brothers and sisters, so he must be a responsible hu*****and. Brothers and sisters would grow up, so the responsibility would end anyway.
My dad appreciated my mom's understanding and they lived together happily. I have never seen them fight over money at all. They pooled their money together and managed, although everyone was poor in China in those days. Then, when everyone started to make good money, my dad also did very well, as a partner of a CPA firm. He passed away 3 years ago and left my mom enough savings to live comfortably without him.
I think several things are very important in keeping a successful relationship
1)understand each other's feelings: my dad loved his brothers and sisters, but he knew his boundary. He prioritized correctly, without hurting anyone's feeling. Same was true from my mom.
2)same goal: both must be committed to make the marriage work.
But it seems to be very difficult these days to find such a good marriage. sigh... Most people only think about me me me.