We asked the BuzzFeed Community about the biggest Simpsons fails they've spotted. Here's what they said.
1. Blinky appearing on Homer's shirt before it was discovered.
2. Homer is shown pulling out his hair when he finds out Marge is pregnant with Lisa in one episode, but in another he seems happy with the news.
3. Ned and Homer met once as teens, and again in adulthood.
4. Ralph's voice changing.
5. Ned's weird neck.
6. Bart's allergies.
7. The changing house.
8. And the vanishing rumpus room.
9. The power plant's timeline changing.
10. Homer and Marge's marriage not lining up with Bart's age.
11. Milhouse's first kiss changing.
12. Smithers' ethnicity changes.
13. And Hans Moleman's ethnicity changes too.
14. The changing timeline of Santa's Little Helper.
15. Abe Simpson's service changing places.
16. Flanders' age is inconsistent.
17. There's a picture of Maggie on the wall when Marge is pregnant with her.
Some submissions have been edited for length and/or clarity.