@Shaokang You cannot compare Serbia with Croatia and Slovenia. They had much more industry and infrastructure in pre Yu time. In industrial terms they were stronger then other socialist states. It’s not hard to check the figures and numbers. One of the reasons of interrepublic conflict was economy. Both Slovenia and Croatia thought that too much money goes for republics who weren’t industrialized.
I used my parents just as an example. I know that there are others in milions who had the same situation.
Did you ever wondered why you can find easily a person in Serbia who is going to tell that Yu was good state, but you will find less persons with that statement in Croatia and Slovenia