Marge says they watch the same shows all the time, while Lisa says that the Itchy & Scratchy cartoons are just pasted together from pieces of old episodes (and pointing out that Ren and Stimpy do it all the time). This comment is a sly joke about the construction of this episode; the blackboard and couch gags are taken from other episodes, there are clips from past episodes, and the interstitials are actually clips from past episodes that feature the family members talking in the kitchen. These three aspects support the idea of this episode being a clip show to the extreme.
Jacqueline Bouvier and Grampa Simpson getting on the bus after the crashed wedding is taken from the final scene of the 1967 movie The Graduate.
Bart's story about Lauradidn't end in heartbreak: she dumped Jimbo after he broke down crying over Moe threatening to stab him, and Laura said that if Bart were old enough, she would go out with him.
Lisa's story didn't end in heartbreak either; she and Ralph became friends.
Homer mentions that Mindy became an alcoholic and lost her job at the plant after his time with her, but future episodes "Team Homer" and "The Twisted World of Marge Simpson" show Mindy as sober and working at the plant. Either Homer lied about what happened to her (whether intentionally or just parroting a rumor he heard) or Mindy went to rehab, got better, and got her job back. It's also possible Mr. Burns simply rehired her because he's not exactly known for having the best memory.
Despite the above-mentioned edit to the "Think unsexy thoughts" scene, Homer's memory of Mindy still includes Mr. Burns releasing the flying monkeys, when he wasn't there to witness that.