Pinkie Pie let out a small breath as she entered her room, her mane noticeably deflated. Today had just not been her day. She woke up with a small ache in her back from sleeping weird, the Cake twins cried nearly all day due to being in a bad mood, and thanks to that just-mentioned fact, she'd mismeasured the batter for some brownies and only realized after they'd come out of the oven, meaning she had to do it all over again. The Cakes were sure to scold her on that, and even though they were lenient because she had to balance taking care of the twins too, it didn't help Pinkie's mood.
She shut the door behind her with her backleg, then walked over to her bed and plopped face-first into it. Not even a hundred Gummy licks would make her feel better now.
Pinkie sniffled from her place on the bed, though it was muffled. "Not even a million billion could. Why did you do that?"
The writer of this story was tempted to act surprised by Pinkie Pie addressing them, but decided against it, especially now that they just wrote that; she would never buy it.
They decided to underline talking directly to her for the ease of reading, though they weren't sure if Pinkie Pie could tell the difference.
Whatever do you mean, Pinkie?
"I only had a bad day because of you!" Pinkie Pie accused, face still shoved into her blanket. "Y-you wrote it that way."
It was true. They did. They couldn't deny that.
"See?"
I'm sorry. I felt like this was the only way I could get you to talk to me on a serious level.
"I can be serious!" Pinkie Pie claimed, pushing herself up. "...Sometimes."
The writer had made their point.
"O-okay, but..." — Pinkie Pie wiped away a tear — "you could've just written me to talk to you, right? You didn't need to make me sad!"
Would you have realistically talked to me if I hadn't? I don't think it's very you to stay in one place for too long unless you're upset.
"I-I guess not," she admitted. "But why does it matter to you?"
Because I want to talk to you. I have no desire in talking to a Pinkie Pie who isn't the real Pinkie Pie.
Pinkie Pie stared down at her bed, brows furrowed.
The writer wanted to let her know that they were listening, but even her knowing that didn't help much.
"T-there isn't a real Pinkie Pie." She sniveled. Her perception of the fourth wall had always been a blessing and a curse. On one end, she could bend the world she lived in at times to do as she pleased, which often worked out in her favor. On the other, knowledge of such a thing meant that she knew this world was not something that was considered 'real'. To be blindingly happy and oblivious to things happening around her was an easy - albeit flawed - way around it.
So the sadness you feel is fake? You wouldn't have reason to be mad at me if it was.
She brought her hooves to her chest, completely unsure. The question was complicated.
"I-I don't know. I guess? I think?" She shook her head. "It feels real to me, but I'm not real, right?"
Aren't you?
"Aren't I?!" She pouted in frustration, flopping onto her back. "D-don't mess with me!"
The writer paused for a long moment to consider where to take this.
If your feelings feel real to you, is that enough? You bring smiles to your friends almost every day; isn't that at least pretty real?
"B-but my friends aren't real either!" Pinkie Pie shouted. "T-they're just... characters, like me!"
The fact that she said it out loud upset her further, the tears coming on more stronger now. The writer desired to reach out and pet Pinkie's head as a form of comfort, but couldn't. They hoped that expressing the want to do so would help her at least a little though.
An idea then came to the writer's head.
And who exactly are your friends?
Pinkie Pie was confused on why she was being asked this, but gave in. "Twilight, Dashie, Rarity, Fluttershy, Applejack," she listed, "a-and everyone in Ponyville, I guess? I have lots of friends."
I didn't write you to have them, did I?
"No..." Her ears flopped. "But someone else did."
And yet you still love them. You couldn't bring yourself to hate them, could you?
She was hesitant, even though she already knew the answer. "No."
Look at the wall.
She didn't understand, but obeyed. She squinted at first, as if unable to see it because the writer did not inherently describe it as being there until just now.
But it was indeed there. It was yellow, though she felt like she already knew that it was.
You're right in that someone wrote you to have these friends, and someone wrote you to love them like family. Someone wrote that your room had yellow walls, and some of your actions may be decided by other writers putting their hand on your character, but what fills the gap is completely up to your own interpretation, isn't it?
Pinkie Pie rubbed her head in mild irritation. "M-maybe? But, you're deciding what I do now, aren't you?"
In a way, yes. In another way, no. I told you that I didn't want to talk to someone who wasn't the real Pinkie Pie, and I stand by that. Your actions and words are written by myself, but I cannot control how the real you would react in this situation. You're already a character, Pinkie Pie, and if I go outside those bounds, it isn't you anyway. I'm writing it, but you are carrying this story, all by yourself, because you're interesting all on your own.
After this conversation is over, people are going to be reading this, because they'll see your face and want to read it because it stars you, regardless of how 'real' you think you are. They'll know you better than they know me, even though I'm writing the thing, because you were so inherently interesting that someone had to turn you into a character with likes, dislikes, and your own personality. I think that's pretty special.
Her eyes softened, but she still wasn't quite out of the dumps. "But... why do you care then? You didn't make me."
No, but as I'm writing, you are my Pinkie and I want to take care of you. I didn't want to make you sad, but it had to happen for us to get here and I want to reassure you when you're in doubt. To reassure a Pinkie Pie who isn't the real one would be a waste. A writer does not write a story to use the characters; a writer lets the characters write the story.
Pinkie Pie grew quiet at that, so the writer decided to go with a different approach.
Tell me, when you get sad, is 'being real' something you think about when you're 'in-character'?
In-character? Out-of-character? Pinkie knew what these meant but couldn't fully convey her thoughts on them.
The talk was even hurting her head, but she tried to continue. "I...I don't know? What do you mean?"
Ahh, now we're getting somewhere. No one would know, would they?
You're made up of many personality traits, Pinkie Pie. While the basics are there for everyone to use, it can be taken in so many different places. There are so many different stories about you, that some would say are 'in-character' and others would disagree. That's because you're complex, which is much more than the average character could be.
Pinkie Pie blushed at the compliment. "Complex?"
I repeat that I didn't want to make you sad, Pinkie Pie, but the fact that you can be sad is just one show of your character. You aren't happy all the time, but optimism is one of your core traits.
And... correct me if I'm wrong, but since you're so knowledgeable about what goes on when people watch you, that means you've seen them, right? I'm sure not everyone is nice, but you've seen people laugh at your jokes and smile when you smile, haven't you?
Pinkie Pie's heart swelled with pride at that, a small smile on her face. "Y-yeah?"
Let me tell you then; that is pretty special. If you think about it, someone made your character out of a desire to see you talk and move around as if someone could just reach out and touch you. They wanted to bring you to life. The happiness you bring to people is real. Very real; sometimes even more real than the happiness other people bring them.
The once semi-deflated mane fluffed up, back to its original state that Pinkie Pie had been in before this whole ordeal. She smiled wide, back to her usual state.
She also poked her head out of the story, just so you could be sure that she was. See?: 
The writer silently acknowledged that allowing her to do such a thing was silly, but that was Pinkie Pie's specialty, wasn't it?
A cupcake then popped out of thin air, landing in Pinkie Pie's hooves. It was the writer's apology for putting her through this.
Do you feel better now?
"Mmm!" She didn't fully answer, gobbling up the delicious cupcake. The writer was ninety percent sure that it tasted like birthday cake, but you'd have to ask Pinkie Pie just to be sure.
We don't know happiness without sadness, Pinkie Pie, and neither would you. You understand now, I hope?
Pinkie Pie nodded eagerly, the shine in her eyes back to its normal bubbliness. She smiled, now feeling so playful that she touched her hooves to the text, squishing and stretching it undernea—HEY!
A joyful laugh escaped Pinkie Pie's throat. She was back to her old self again.
You know, I think there's a party you're supposed to be planning for.
"What?" She blinked.
Yeah, and I think you only have one hour left to prepare.
"Wait..." She gasped. "You wrote that on purpose!"
The writer thought to themself for a moment; maybe it was a half hour instead?
Pinkie Pie squinted, but couldn't stop the smile on her face.
She bounded out of her room, off to throw the party that most definitely had not just come into existence.
The writer was certain it'd be a great one if Pinkie Pie was planning it. What a good character.
Author's Note
I... honestly have no idea what I just wrote. 
~~This is why I only write Romance.~~
