The boys start their first day of 4th grade. After a bad encounter with their new teacher, they seek the help of two nerds to go back in time to 3rd grade.
4th Grade contains examples of:
- An Aesop: Mrs. Chokesondick explains that its better to move beyond than move backwards, and the past isnt as awesome as you may think. Mr. Garrison also learns to come out the closet with his gayness. That is until Principal Victoria states that the school doesnt hire gay people.
- Bittersweet Ending: Garrison's plotline ends with accepting he's gay, but not being rehired because he's gay
- Brain Bleach: Principal Victoria, Mr. Mackey, and Chef all needed this after Miss Choksondik accidentally exposes her nipples
- Call-Back: Mr. Garrison's novel Valley of the Penises from Cherokee Hair Tampons is mentioned
- Also Garrison supposedly soliciting sex from a student is mentioned again
- Early Installment Weirdness: When the boys suggest mooning the teacher Butter of all people offers a more vulgar idea of mooning her with their groins sticking through their legs.
- Extreme Doormat: For all her screaming, Miss Choksondik wasn't very effective in disciplining the kids until Mr. Garrison helps
- Everyone Has Standards: Even Chef and Kenny were disgusted by Miss Choksondik's enormous boobs
- Gag Boobs: Ms. Choksondik has these, ironically Kenny is the only one to have a problem with this.
- Hidden Depths: Butters knows more about Star Trek than the nerds who were fighting with each other
- It's All About Me: Both nerds would rather be right about the number of Star Trek episodes than introduce an invention that would be a scientific breakthrough.
- Minor Flaw, Major Breakup: A friend example, the two nerds ended their friendship over the number of Star Trek episodes
- Running Gag: Clyde cries for the first time in this episode.
- Take That!: Huckleberry Finn is called a homoerotic novel
- They Killed Kenny Again: Kenny dies after being dragged across a road by Timmy's wheelchair.
- Transparent Closet: Mr. Garrison finally comes out as gay, but the staff knew that.
- Unfortunate Name: Ms. Choksondik. Supposedly, Trey and Matt tried to make it less obvious by giving it a certain accent, à la Edna Krabappel, but none of them were nearly as funny as just saying "chokes on dick." Funnily enough, the boys don't catch on to this and corrupt her name into "Makes-me-sick".
- Wham Episode: After spending the first three and a half seasons in the third grade, the boys enter the fourth grade here, where they remain as of Season 22.