Ok so I was thinking about this. We see some way the three other main characters in South Park characters have birthdays. But never Kenny, ik his parents are poor but there isn’t even a “happy birthday Kenny” in the show at all well the others get it. But my theory is that because of Kenny’s dying and being reborn, he technically doesn’t have a true birthday. 3/22 was his first birthday so that’s his “official birthday”. I know it sounds crazy but you just have to hear me out.