Towards the end of Monsters University, you find out that Sully and Mike worked for the Abominable Snowman in the mail room. But in Monsters Inc., his reaction isn't what you would expect with Sully and Mike working for him. Furthermore, his explanation of why he thought Sully and Mike are friends seems strange if he knew them back in the mail room.
When Mike and Sulley are first shown their room at the fraternity house, the light switch is under the top bunk bed. In subsequent shots it has moved closer to the door and is no longer directly under the bed.
There is a slight difference in Chet's size compared to Mike's in two separate scenes. In one scene, it showed that he was slightly larger than Mike when he told him off at the fraternity/sorority party, but later on, in the movie, it somehow showed that they were almost the same size when Chet appeared beside Mike sipping his mug.
Mike as a young monster at the start of this movie, voiced by Noah Johnston, does not have a New York accent like he does an adult.
When Mike punches the bed to show Sulley all of his shedded fur, much of it falls on his head. In the next shot, the fur has disappeared.
Mike registers for his classes during orientation. At actual colleges and universities, registration for classes typically happen during the middle of the semester.
The junior novelization of the film incorrectly lists the heading of one of the school newspapers as "Cutie Kappa".
When Mrs. Graves is counting students, she counts to 19 and then notices that Mike is missing, which means that there are 20 students in the class. If this were the case, he wouldn't have to pair up with the teacher. However, one of the students could have two heads, similar to Terry and Terri - though they are considered two separate entities, Mike could not conceivably pair up with one of them while the other already has a partner.
In Monsters Inc., Mike tells Sulley "You've been jealous of my good looks since the fourth grade, pal." However, according to this movie, they did not meet or become friends until they went to college together. The producers have stated that Mike was merely using an expression.
In Monsters Inc, it's revealed that Sulley's first name was James. But in this movie, he said that his name was Jimmy.
Jimmy is a nickname for James. It's very likely that Sulley was called Jimmy before being called Sulley.
Jimmy is a nickname for James. It's very likely that Sulley was called Jimmy before being called Sulley.
In the library, Greek Council president Claire says there are only two teams left; but this is not true until the final event. She was actually referring to the number of teams left in the "Avoid the Parent" event.
In the cabin scene, a record player has the record spinning in the wrong direction.
During the final scare games event a monster walks into the scare simulator. When he comes back out he is shorter.
Despite the fact that Squishy's mom was listening to loud music, she didn't lose her hearing.
In the house party scene, a modern dance song is played. Assuming that this movie takes place years before Monsters Inc. (which was released in 2001), this song shouldn't even exist.
Mike has braces at the age of 6. Most people have braces in their teenage years, and some adults even have braces as well.
Monsters University is said to have founded in 1313, way before the screams the monster world collects would've been useful for energy.
The final exam file for the first student has the child's location as Texas. The location should be followed by the country where the child is from (U.S.A.).
Don Carlton's final exam file lists the boy's fear as spider monkeys. The boy is from Tokyo, Japan. Spider monkeys are found in tropical forests of Central and South America, from Mexico to Brazil. Therefore, spider monkeys are not native to Japan.
The textbook chapter on the Cobra Hiss explains the eyes need to be opened to 110% capacity, but the diagram wrongly depicts this as an angle with the eyes open at 110 degrees.
Don tells Sullivan that he's scary even with his pink polka dots. They're not pink, they're purple.
Terry Perry is obviously voiced by Sean Hayes while Terri Perry is voiced by Dave Foley. The credits and encyclopedias mistook Terry to be voiced by Dave Foley and Terri to be voiced by Sean Hayes, since Dave Foley's voice was heard from Terri and Sean Hayes' voice is heard from Terry.
The names of the President and VP of the Greek Council are never mentioned by name in the film. Their names are: Claire Wheeler and Brock Pearson.
The cover of the junior novelization depicts Mike wearing a university jacket. Mike does not wear a university jacket at any point in the film.