* In one episode, Mr. Ratburn was shown to be overweight as a kid, before he began playing ping pong and lost weight. It's safe to assume his love of cake helped him gain weight in the first place.
* In the episode where Mr. Ratburn's class meets their doppelgangers, Arthur's is named Chester. It's a reference to President Chester A. Arthur.
* Francine's overreactions to Arthur being mean to his sister make sense if you realize that she's the younger sister in the family and Catherine can be distant.
* At first glance, the main title sequence with Brain dangling his feet in the pool doesn't seem to make sense since a season two episode established that Brain is pathologically afraid of water. However, his fear of water might explain why Brain then mistakes Mr. Ratburn for a shark and has such a frightened reaction.
* In "To Eat or not to Eat" the Big Boss bars were extremely addictive and toxic, meaning that the main ingredient was basically a recreational drug. Which means it most likely caused brain damage when it was eaten...and almost every kid in the school was addicted to them...
** It's also rather horrific to imagine a bunch of elementary-school age CHILDREN going through the nightmare of withdrawals.
** Even if the Big Boss bars were banned...addicts don't give up their habit that easily. Considering that [[DoesThisRemindYouOfAnything some children were seen buying as many as possible and hoarding them, with others even functioning as "dealers",]] there are probably quite a few Big Boss bars still floating around. That CorruptCorporateExecutive may have [[MoralEventHorizon introduced a whole new drug trade]], one [[AdultFear predominantly catering to young children]]. And no one even seems concerned about this...
** Possibly even worse, said bars were apparently toxic to the point that their creator ran rather than eat one. And ''radioactive''. And, as stated before, hundreds of kids were eating them nonstop. And they are probably still being eaten by some. [[AdultFear Dear Lord....]]
* In the episode with the Riddle Quest Game Show, Arthur lost on purpose because he was afraid he would end up being on the show forever and have to change schools. The same thing might eventually happen to Charloette!
The Brain is terrified of water...and yet one of the title cards (which is an expy of a different title card featuring Arthur) features him swimming by the audience...