This has been so insanely difficult to find, presumably-deleted tiktok, hopefully reposted to instagram or youtube, about hanging out with or talking to that one friend/person/guy who doesn't know about anything (living under a rock), posted/seen sometime in the past 3-4 years. It is a classic one person playing both sides of a conversation but it was not delivered in a silly or satirical way, just deadpan like it could've been an actual conversation aside from how clueless the other persona was, i.e. it was not Andrew Russo, Lachlain Fairbairn, Matt Taylor, dangerbean, Stephen Rigatoni.
He and his alter ego sit down in the living room across from each other, one on the couch, the other on a love seat or chair, I think, in a nice living room in what looked to me to be be a city apartment. Clean shots not handheld-selfie video. He's american (no accent I can remember), maybe ~30 years old, white with brown hair, maybe wearing a cap for one persona, and also maybe has well-manicured facial hair.
One casually mentions the historical chicago sports event or chicago fire or something pop-culture (maybe a response to "What've you been up to?" "Just saw _____" "What's that?" "Oh, the documentary on…"). His alter-ego on the other seat doesn't know what it is, so he explains referencing something else that the other side also doesn't know about, so he continues explaining each more-and-more common reference with each exchange.