“That ‘90s Show” Episode
This, to many a Simpsons fan, is considered one of the worst alterations of continuity the show has ever produced. Sure, once you cool off from your initial rage, it’s not the worst episode ever, but it does alter the past of the show with a new story that is not nearly as endearing. Without going into too much detail, the plot claims that Homer and Marge didn’t get married right out of high school or have Bart as quickly, either. Instead, Marge went to college on Homer’s dime and fell for her instructor, leaving Homer. Homer, distraught, then started the grunge music movement with his band, Sadgasm, until Marge realized she had made a huge mistake and went back to him. It’s best to think of this episode as either a prequel to the classic episode “I Married Marge,” or to forget it entirely.