According to this episode, Principal Skinner has been an interim principal for 20 years.
The gym teacher says that Coach Lugash "defected into East Germany", but in the episode "Children of a Lesser Clod", Lugash is said to have escaped from East Germany by cartwheeling over the Berlin Wall.
In the part with the Itchy and Scratchy cartoon, you see Itchy pour the butter on the toast and Scratchy's eyes are nowhere to be seen but in the next shot, Itchy takes a bite out of one of Scratchy's eyes.
When Homer is throwing the frisbee to get Bart out of the tree, we see the pieces of wood nailed onto the tree for Bart's tree house, but then moments later they are gone so that Lisa can use her gymnastics to get to the top.
When Bart is eating (slurping) his soup in the bubble, Homer gets mad and fills Bart's bubble with water. When Homer picks up the bubble, the soup liquid is nowhere to be seen, however the spoon and the bowl are seen floating in the bubble.
Skinner is the only one to get chocolate cake splattered on him.
One of the girls in Lisa's gymnastics class jumped out the window just as Lisa got there, she returns a minute later on the balance beam.
The night that Lisa sneaks out to go to the poetry reading, as Homer walks by the kids rooms' saying good night, Bart and Lisa's rooms seem to have switched positions.
Skinner's estimated life as listed on the plaque is "1953–2010" making him only 57 when he dies (though if he were born in 1953, he wouldn't have been old enough to fight in the Vietnam War in the 1960s).
Sherri and Terri are participating in the 2nd grade gymnastics class but they're in the 4th grade. This could imply that the twins were failing gym class in their year.
It is revealed in this episode that Moleman is 80 years old, although in "Duffless" revealed that Hans is 31, and only looks old because of severe alcoholism.
The Itchy and Scratchy episode's production code was DABF06 which is really the production code for the episode of The Simpsons entitled "The Bart Wants What It Wants".
The Big Ten, whose name is part of the episode’s title, is a real conference. Despite its name, it has twelve schools; Springfield University is not one. The schools are Northwestern, Nebraska, Minnesota, Michigan State, Michigan, Iowa, Illinois, Indiana, Purdue, Penn State, Ohio State and Wisconsin. Rutgers and Maryland joined during 2014.
Nelson runs around an entire block, just to laugh at Bart's bubble twice.
When Homer and Marge scold Lisa for going to college classes at age 8, she brings up Doogie Howser.
When Lisa wakes up from her dream where she meets John F. Kennedy, she says "Ich bin ein gymnast," parodying John F. Kennedy's famous speech "Ich bin ein Berliner."
When Lisa gets a lift from the college students, the song "All Star" by Smash Mouth is playing on the radio, famous for being featured in the 2001 film Shrek.
When Lisa is watching the Itchy & Scratchy cartoon, the brand of butter Itchy makes is called "I can't believe it's not Scratchy," a parody of "I Can't Believe It's Not Butter!"
When Lisa sneaks away from school to go to college, the theme tune from the Pink Panther can be heard.
When Bart doesn't feel well after the mosquito bite, only the top half of his body is shown in a shot which could have possibly have shown all of his body.
During the Itchy & Scratchy Cartoon "Butter of Dead", when Itchy takes the milk made from Scratchy to turn it into butter, there's no tap on the barrel but then a taps appears from nowhere on the left.