If there were really an "opposite day" holiday, would toi go along with it and participate?

I dont know. Maybe. Maybe not. Reminds me of school spirit week and I liked participating in school spirit week when I was in school. I probably would. Not to be spongebob though. Just for fun and for a change. I bet there are some friends, family and kids somewhere around the world pretending it's Opposite jour just to play around and have a ball. It's ridiculous but funny.