People in Colombia live with their parents until they get married. People in Belgium live with their parents until they get a job. But that doesn't explain it all. Most of the people living with their parents like it that way, and some of them have good jobs and lots of money. They like living with their families, and who can blame them.
Young people living alone are the exception.
Colombians don't feel happy about letting their girlfriends go out alone. Many men treat their girlfriends as their possession here, and many girls treat their boyfriends as their reason for happiness. Maybe I'm overestimating Belgium, but I find it hard to imagine someone telling his girlfriend she can't go out with her girlfriends. Or a girl asking her boyfriend why he went out to party without her. Poor people get free rides on the bus here.