You're right, it's a truly hilarious festival really.
However, it pails into insignificance when compared to another ancient festival. In it the high and mighty and the lowly agree to change places for one day. The wealthy act as the lowly for one day (even the priests I think) and the lowly lord over them - I'm not exactly sure what that festival was called - or where or why that took place. It might have served socially to be cathartic I guess...
Maybe someone can step in here - and enlighten us... Anyone?
Saturnalia. Which evolved into Christmas.