When Homer is driving his car, he is disappointed to hear "(They Long to Be) Close to You" by the Carpenters, but is in better spirits when he changes the station to hear "The Joker" by the Steve Miller Band, to which he sings along. However, "Close to You", plays in Homer's mind when he first lays eyes on Marge, indicating love at first sight. "The Joker" plays over the closing credits.
Jacqueline's hair is a slightly lighter shade of blue than Marge's
A brief scene of "I Married Marge" is shown (the part where Dr. Hibbert tells Marge that she's pregnant and Homer yells, "D'oh!"), but it would not be until the following season that that story would be told in its entirety.
Homer's guidance counselor's door reads M-Z, but the counselor says N-Z.
Homer dismisses English class as worthless because "I am never going to go to England!" However, Homer tours England in "The Regina Monologues". He presumed he'd never go to England, he was 16 at the time and wanted to skive off English.
Although they think it is the first time they met, Marge and Homer will find out that when they were little kids they met at a summer camp in The Way We Weren't. This isn't a goof. They didn't recognize each other. Marge never gave a name and Homer gave a fake name. They unintentionally looked different when they were kids, unfortunately.
When Homer is given the pamphlet about the Power Plant he is told it is a job that does not need a college education yet in "Homer Goes to College" Mr. Burns is ordered to enroll Homer in college-level nuclear physics classes or else face sanctions from the Nuclear Regulatory Commission.
Marge says they were seniors in high school together, so that would mean that they are the same age. However, it has been established that Homer is 39, and Marge is 34. Is it possible that Homer got held back in school five times (considering that he's not book smart at all, this could be a believable conclusion to draw)? He sure didn't look 23 when he was a senior. This is just one of the many weird things in the show about Homer aging, but nobody else.