List of inconsistent continuities

This is a list of all the continuities in the series that have been broken.

Continuities Regarding Characters
This section is for character back-story events that conflict with other events mentioned in previous episodes.

Simpson Family

 * In Much Apu About Nothing, as Lisa mentions that the Simpson family were original immigrants, Abe recalls how his family originally lived in the unnamed "Old Country" and eventually moved into the Statue of Liberty.
 * In The Blunder Years, Homer recalls his child years at the age of 12, which took place "30 years ago". This implies that he is 42.
 * In Angry Dad: The Movie, Bart mentions that he watch the early episodes of SpongeBob SquarePants as a toddler, a show that debuted 10 years after the debut of the Simpsons series.
 * In Kill the Alligator and Run, the Simpsons were banned from Florida, as well as every other state other than Arizona and North Carolina. However, in later episodes, the Simpsons have been to many other states such as Delaware, Missouri , Washington D.C. , New Jersey , California , New York , Nevada , Oregon , Vermont , Illinois , Utah , as well as Florida , twice after Season 12.

Flanders Family

 * In Lisa's First Word, Ned and Maude first introduce themselves to the Simpsons when they move to Evergreen Terrace.
 * In Lisa the Vegetarian and The Bob Next Door, it is shown that Ned's other relatives use the same nonsensical talk as he does.
 * In Hurricane Neddy, it is revealed that Ned's parents sent him to see Dr. Foster 30 years ago for anger treatment. It is also revealed that treatment also resulted in his trademark nonsensical jabbering.
 * In Viva Ned Flanders, Ned Flanders reveals that he is 60 years old.
 * In Dangerous Curves, Homer and Marge in their dating years first meet Ned and Maude, who just got married. This takes place 20 years earlier.

Mr. Burns

 * In Burns' Heir, when Mr. Burns' life flashes before his eyes, we see a brief flash back of him as a baby, who fires his nanny.
 * In Rosebud, Mr. Burns grew up in a poor family as child, until a twisted, loveless billionaire came by and offered him to come live with him. He was also related to George Burns.
 * In Monty Can't Buy Me Love, Mr. Burns mentions that his first "gay" experience was when his father took him on a picnic at age 6.
 * In Them, Robot, Marge comments that Mr. Burns was originally a nice man when he first came to Springfield.

Waylon Smithers

 * In The Simpsons 138th Episode Spectacular, Troy McClure mentions that Waylon Smithers is in his early 40's.
 * In The Blunder Years, Smithers' father, Waylon Smithers, Sr. saves Springfield from a nuclear meltdown 25 years earlier, but shorty died of radiation overexposure, leaving Mr. Burns to raise Smithers. This would have made Smithers only in his late 20s instead of early 40s.
 * In Bye Bye Nerdie, Homer recalls beating up Smithers in middle school.