You know how obsessive fans are called stans? Well, this concept pretty much writes itself at this point. So Stan becomes a big fan of something and Cartman starts calling him a stan. Stan is utterly confused why his name is suddenly used in such a negative way. This would then ultimately lead to Stan becoming the Stan from the Eminem song, where he grows a resentment for the person he’s a fan of and sends them about angry letter. He also blames his parents for making him a stan by naming him Stan.