Crossdressing Tricks
A concept that was especially celebrated during the Feast of Fools was inversion. That meant those on the lower rungs of social hierarchy could enjoy feeling like the upper class for a day. Students would parody teachers, rulers, and clergymen. Men would dress as women, and women would dress as men. This would accompany a lot of dancing, singing, and of course, drinking.
Monks Gone Wild
The Feast of Fools was all about breaking the rules, and that gave monks and nuns a chance to let loose once a year. A lot of the festivities actually took place in churches. It is not surprising that those who spent the majority of their lives being pious would love to take advantage of one day of partaking in usually forbidden behavior.