- "Hey James, I know how you can get back at that dumb Irishman Patrick McReary! Give him amnesia! That way he will not remember anything. Then, make him think he works for you and Joel. You can turn him against his own siblings! Think of the possibilities!"
- ―A text message to James Johnson from Giovanni Ancelotti
The Amnesia Act of 2015 is the fifth comic in Season 4 of Sibling Rivalries, and is the 34th comic overall.
Joel, James, Marco, and Trevor have been released from Portage County Juvenile Detention. On recommendation from Giovanni Ancelotti, Joel and the gang plan to give Packie amnesia, then make him believe he works for them. When Joel turns Packie against his siblings, it is up to Francis, Gerry, Derrick, and Kate to try to get the old Packie back.
♥ = character's debut
♠ = character does not speak throughout comic
♣ = character is mentioned only
♦ = character appears in a speaking/non-speaking cameo only
- Patrick McReary
- Francis McReary
- Gerald McReary
- Derrick McReary
- Kate McReary
- Aiden Wilson
- Maureen McReary-Wilson ♦
- Hector Wilson ♦
- Joel Gonzales
- Jose Gonzales
- James Johnson
- Marco Johnson
- Trevor Johnson
- Officer Charlie Macias ♦
- Officer Fred Miller ♦
- Louis Wilson ♣
- The comic's title is a pun on The Amnesty Act of 1872.
- This is the fourth comic (as well as the first comic outside of Season 1), to have "The End!" and the date the comic was finished at the bottom of the last panel, rather than being in its own separate box. ("Gonzales Vs. McReary", "The Curse of the Milderbeast", "San Salvador's Story")
- Second comic to have numbers in the title. ("Locker 239")
- Trevor, Charlie, and Fred reappear from "Like Father, Like Sons (And Daughter)". Joel still has a paintball stain on his shirt when Salvador Martinez shot him with his Paintball Launcher in the said comic.
- Marco and his brother Trevor's last names are revealed to be Johnson; they are also James' cousins, hence the same last name.
- It is revealed that when they were little, Francis would feed and change the diapers of his younger siblings.
- Joel dressing up as Hector and luring Packie into giving him amnesia is a reference to the Cletus Comics comic "When The N.O.O.S.E. Attack!", when Anti-Cletus dresses up as Cletus's wife Gal-Bot, then tricks him into becoming trapped.
- It is revealed that James Johnson and Giovanni Ancelotti have Facebook, since Giovanni messages James through the said website. James also has Kik, due to him having the Kik notification icon on his display bar.
- Giovanni also does not have a profile picture for his Facebook account, which further keeps his identity a secret.
- This is the first comic to show a character's full smartphone screen (in this case, James Johnson, although his phone has a large crack in the center, possibly referencing his careless life as a delinquent).
- The wall inside of the Wisconsin Elementary School is still shown destroyed from Locker 239, with caution tape seen covering the area Mark Sanders ran his mother's car through.
- The boy's restroom of the said school appears for the first time (although the door to the restroom appeared in the previous comic, Wouldn't It Be Nice?).