When i was a kid I remember "so" was the first big cultural movement in slang. We went around "PSYCH!" "so what?" "So what???" "PSYCH!" 

Then one day on like second grade a kid was like "so?" And we were all like 😯😯😯😯😯😯😯😯😯😯😯😯😯😯😯 and the one pyro kid was like 😮
And that's when we started shortening things. Great day in history. 

We went from what's happening to what's up to sup to suh doo to 🤷🏽?