“It was Pope Gregory XIII who, in 1582, would unknowingly give rise to the world’s silliest holiday. He issued a decree ordering that all Christian nations adopt a standardized calendar, called the Gregorian calendar. This moved the new year from the end of March,( I think it was around March 23 and in those days they celebrated for 8 days.) to the first of January, causing a great deal of confusion for some. Those poor saps who were ignorant to this new tradition or simply didn’t want to observe it were mocked as ‘fools.’”
According to History.com, this mocking included attaching paper fish to the back of the fools, or “’poisson d’avril’ (April fish), said to symbolize a young, easily caught fish and a gullible person.”
Don’t be afraid to pull (good-natured) pranks on your friends either! You’d be in good company – St. Philip Neri and Blessed Pier Giorgio Frassati were both especially known for being jokesters.