Your Best Friend, a Notebook

"Bro, this is going to blow your mind."
"It'd better."

Your friend Sam just resorted to spamming you with text messages for an hour straight until you agreed to come to his house, to say you're aggravated with him would be an understatement. The scrawny blond is visibly shaking with excitement as he reaches under his pillows and pulls out what you were to go across town to see.

A dusty old notebook.

It would seem that your disappointment is evident, because he instantly starts stammering out an explanation.

"This book can change anything, people's thoughts, bodies, objects, laws. Anything written in it becomes truth!"

He sighs when your expression doesn't shift in the slightest

"Fine then. Seeing is believing," he pulls a pencil from his pocket, opens up to a random page and jots something down, his hands still trembling slightly "see? I've completely transformed!"

Scanning over him multiple times, you genuinely cannot find any changes in his appearance. You're certain you'd notice with how.. unique his physique is. Fluffy, chin length blonde hair frames a gorgeous face that makes most women swoon with envy, and the rest with lust. While the top half of his body is quite slim his hips flare out and his legs are undeniably shapely. He's never grown a hair below his neck and he's quite short, to the point that he still would be even if he were an actual girl.

Before now he's never given off any signals that any of it bothered him, but you guess that he's been bottling up his distress and it's now bursting out in a fit of hysteria.

"Listen man, i'm not really equipped to handle this. I think therapists are pretty cheap these days-"

"WHAT? How do you not see that i've turned into a... into... uh..." His face quickly shifts from annoyance, to confusion, to panic "Wait, I can't remember what I changed," he opens the notebook and rapidly flips through the pages, "what the fuck!?" Due to your vantage point of towering over him you can see that all of the pages are blank.

"All I can remember is that it was a reference to some meme-" He goes silent when he flips to the last page and finally finds some text.

Mechanics of the Notebook

The notebook can change all things without any conceivable limitations, the notebook is oriented to doing so with stealth. When making changes to objects and other people, none except the user will notice a difference (unless otherwise specified). When making changes to oneself, not even the user will remember what changed (unless otherwise specified). All text in the notebook is invisible to those who don't remember it (disregarding this page).

"Well that's fucking stupid!" Sam yells out, he flips to another page and presses his pencil against it "Fine, the walls of this room constantly change color and John is aware that it isn't normal."

You glance away from him and nearly have a heart attack when you see the walls shifting colors like a strobe light. You stare at the unnatural phenomenon with awe and Sam asks smugly "Ready to believe?" It's all you can do to just nod slightly.