'The Simpsons' Broke a 27-Year Rule With One Controversial Episode

As far as the citizens of Springfield are concerned, what you see is what you get on The Simpsons, now entering its 38th season. Homer (Dan Castellaneta) is an idiot, Moe (Hank Azaria) is surly and depressed, Comic Book Guy (Azaria) is perpetually sarcastic, and so on. Likewise, despite being a series that famously eschews continuity, there are instances where an element of a character's life story is canon: Ned Flanders (Harry Shearer) was raised by beatnik parents, introduced in Season 8's "Hurricane Neddy"; Marge (Julie Kavner) had parents Clancy and Jacqueline and, of course, her twin sisters Patty and Selma (Kavner) growing up; while Homer was raised by Abe Simpson (Castellaneta) alone, after his mother, Mona (Glenn Close) left them and went into hiding.