December 16th is polygon donut day. On this day all donuts must be cut to look like a polygon. You get arrested if you eat a donut on December 16th that isn’t a polygon.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.