And were reformatted to appeal to nationalistic allegiances
That's how it started for me. I just started watching the world cup and Euro Cup @1990. Then I'd started watching the USMNT qualifying games after the 94 World Cup. Then I started following various Bundesliga teams (Bayern, Bremen, Schalke, etc) in the UEFA Champions League @1998. Finally I adopted a BPL team in 2010 - Liverpool after Fenway Sports Group bought them.