The thing that everyone knows about but can not explain. It happened one time, it may never be repeated, can be used to engage in secret conversation about the subject to someone else who knows of its origins.
Guy 1: "Dude, it's really cold today!"
Guy 2: "So cool."
Guy 1: "Let's go somewhere private, I don't think Guy 3 knows."
Cj So Cool
A YouTuber from Gary, Indiana with almost 5.1 million subscribers and lives in a 15,210 square ft mansion in Henderson, Nevada that he calls "So Cool Land"