Before marriage, you are free to do things on your own, spend a lot of money for things that you like, can go to many places, drink, party and can have many girlfriends or boyfriends at the same time. But after marriage, you already have responsibilities to your partner and children. So instead of spending your money and time to nonsense things, you save your money because you want your family to be financially stable. You are already thinking not just about yourself, but also about your family. So in every decision you make, you dont think about your own good but also for your family's own good.