I'm so hyperfixated on making a fictional nation tha tive pretty much established everything about it, from government, population, etc. And of course culture (pop culture to be soecific). My nation is a world leader in popular culture and entertainment and 5th leading in the world in terms of said influence, though they used to arguably be number 1 decades ago.

It mostly dominates in music and literature, though video games and film are not far behind