This sentence is confusing... "found" with "society" sounds like it would mean "initiate". But then why would it be in the past tense? Can't tell if "that's just how it is in Korean" or if this instead means we "found" the society like in a game of hide and seek.
As with many Duolingo sentences, this sentence has little application in real life. However, my research leads me to believe they mean "found" as in it was lost and they found it, not "found" as in they founded (established) the society.