I've unilaterally decided the origin of "Be there or be square" came from the dad joke style sentiment (also of common humor style in the early-to-mid 20th) that if you're not going to be "around," you're going to be a square.
@theunabeefer Is one still square if one gets a round tuit?
@GeorgeG Oh I didn't counsel with the wife... She'll just tell me I'm an idiot. Lol... She'd be right, of course!
@theunabeefer As it is written -- He who possesses both a round tuit and a spotted dowel is thrice-blessed, with the third blessing being allowed to decide unilaterally. (pending counsel with wife)