I don't know much about North Korea geography (rivers, lakes) but where I am originally from, swimming was something boys learned when playing as children. It didn't cost anything, you were just using local lake. So this assertion is bullshit, unless this is a cultural thing about North Korea.
Probably. The difference here is that I freely admitted I have no knowledge of Korean culture. You on the other hand are an arrogant arsehole, dismissing someone else's experience with no knowledge whatsoever.