Senior skip day is a rite of passage. I don't know why everyone does it, but once during your senior year all the seniors don't show up when everyone else has to just to say "Hey, we are seniors. Pay attention." Like that is needed to be said.
Unless, of course, you participate in some sport/activity and have a game/performance that day and the rules state that you have to attend school to participate. I was in the backing band for our show choir of my school that happened to have a performance that night. So my buddies and I had to attend school. But nobody were in our classes. (They were all skipping)
So what did we do?
10 minutes of hilarity, trying to "discover" the Possible Theories as to why people weren't in our classes.
A thanks to Klick's Corner for posting the video. I recommend watching all of it (over 2 clips) just to watch me stab myself, hit myself with a pole (twice) and play the gong with my head.
As yes, I had really long hair in high school, no beard, and no gut. Good times.