I was thinking about this lately since GC is about to be 25. I've certainly learned a ton about the Greek system, but what about random things?
Today, a student actually walked into my classroom wearing a shirt that read, "I LOVE MILFS!" I yelled at him and sent him to the office and he kept muttering that his other teachers had said nothing. He was mad because as the resident ancient teacher, I knew what it meant.
I should have told him that I learned it on this site years ago.