So, I watched the entire Simpsons series up to Season 25, I know people usually think that the show has gone downhill because the characters' personalities change, but honestly, I don't seem to notice many differences in the Simpsons characters' personalities, Homer has always been a childish, well-meaning, neglectful, arrogant and selfish father, Marge has always been kind and well-meaning but also hypocritical and arrogant, Bart has always been a spoiled, spiteful and destructive child with a friendly side and Lisa has always been depressed but also kind, intelligent and critical of other people's ignorance, maybe the only character that has really changed in terms of personality is Ned Flanders.