The Simpsons has been retconning Bart Simpson's controversial origin this season

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"Bart’s controversial origin story claimed that his lack of intelligence was hereditary, but Homer has seemingly forgotten this fact in The Simpsons season 33," says Cathal Gunning. "Although Bart is nowhere near as bumbling as Homer in The Simpsons, he’s also not as unusually intelligent as his sister Lisa. The Simpsons once provided an in-universe explanation for this disparity, although Homer has seemingly since forgotten about this explanation."