Memory Book is a sub-mode in Yeah Jam Fury: U, Me, Everybody! consisting of a notebook used by the three main protagonists: Yeah, Jam, and Fury. They use the Memory Book as a journal to log their adventures and communicate with each other, due to being unable to do so normally. As a mode, the player can use it to view the stickers and entries they have unlocked, their gameplay statistics, and an unlockable cutscene.
- Main article: Memory Book/Entries
Entries are the passages in the Memory Book that the three protagonists write with each other. Each entry is unlocked by unlocking its corresponding sticker, each of which has a unique image, name, and unlock requirement. With the exception of four secret entries, all of their names and requirements can be previewed in the Memory Book before being unlocked, but to view their images and the entries themselves, the player must unlock the stickers.
There are 50 entries and stickers in total, and each is tied to a corresponding achievement sharing the same name, image, and unlock criteria.
The stats section of the Memory Book contains various statistics regarding the player's session of the game. It includes the following statistics:
- Total Stickers: Number of stickers the player has collected.
- A-Sides Beaten: Number of A-Side levels the player has completed.
- B-Sides Beaten: Number of B-Side levels the player has completed.
- Blocks Fired: Number of blocks the player has fired with Yeah.
- Boosts: Number of boosts the player has made with Jam.
- Blocks Broken: Number of blocks the player has broken with Fury.
- Refoots: Number of times the player has refooted after falling.
- Transitions: Number of times the player has switched between Yeah, Jam, and Fury.
- Stages Made: Number of levels created with the Stage Builder.
- Blocks Walked On: Number of blocks the player has walked on. Note that blocks can be repeated.
- Mangos Collected: Number of mangos the player has collected.
- Game Complete: Percentage of the game the player has completed, including levels and stickers. Completing certain sets of content unlocks images next to the name of this stat.
- Total Play Time: Amount of time in hours and minutes the player has spent playing the game.
- Favorite Stage: Name of the level the player has completed the most.
This menu also displays the player's Steam profile name at the top, and a small button in the bottom right corner allows the player to erase all game data.
After completing the secret final level The Ghost Lingers, a special cutscene will play. The player will then be able to view it at any point from the Memory Book in the section named "The Drawing".
This cutscene takes place immediately after the completion of the level and after Yeah writes the That's A Little Different... entry in the Memory Book. It shows him lying down on Yellow Blocks while drawing on a piece of paper ripped from the Memory Book. When he finishes his drawing, he sits up and excitedly takes a bite of the ghost pepper, which burns him for a moment and causes him to frown. He then switches to Jam, who looks at the drawing and laughs to himself. As Jam rubs his face, he switches to Fury, who gets enraged for a moment before calming down. Fury then drops the Memory Book and drawing on the ground and switches off-screen, presumably switching to Jam and running off. The drawing depicts Yeah, Jam, and Fury together with "Can't wait to meet you!!" written on the bottom.
- The special cutscene that plays in the "The Drawing" section of the Memory Book is also used in the game's announcement trailer, except the background resembles the Sky theme and the ghost pepper is replaced with a mango.
- As a reward for being the first player to reach 100% completion in the game, the player Bedoop was given a framed copy of an official Memory Book entry featuring his character, who is also named Bedoop. It is the only known copy of the entry that exists, as it has not been made publicly available.
- According to the game's developers, this entry and Bedoop are canon to the game, though neither is present in-game.