Also, the episode has a new opening scene. This was the first big change of the intro since Season 2.
The HDTV transition is referenced in this episode's chalkboard gag, "HDTV is worth every cent."
The idea of the change comes from Matt Groening's interview to the New York Post: "The clouds at the very beginning of the main title were always unsatisfying to me. My original direction to the animators was to make the clouds as realistic as possible, and as we go through the clouds we enter this cartoon universe of The Simpsons. Finally, after a couple of decades, they've gotten closer to what I had in my mind. Not perfect, but better."
Maude Flanders is seen crushing on Homer in high school, although a few episodes back teenager Homer and Marge were picked up by an adult Maude and Ned who were married.
Homer dived into the sauce, however it was boiling hot and therefore he would have been severely burned.
It is shown that Smithers was already working for Mr. Burns when Homer went to high school, meaning that he is older than Homer. However, in "The Blunder Years" it is shown that he was a baby when Homer was 12 years old. On the other hand, in a flashback of "Bye Bye Nerdie", it was shown that both were studying together at the same time.
During the school band scene in the intro, Jessica Lovejoy is not colored correctly. This was fixed in the following episode.