"I had the weirdest dream last night," Rainbow Dash said.
Twilight listened, but she wasn't listening. She kept trying to smile and nod and agree in what felt like the right places in the conversations she hadn't been completely involved in, but she felt like a fake. An impostor. The puppeteer guiding marionette Twilight through her day. And any moment, she'd slip up and break character and all her friends would know. Just what they would know wasn't exactly clear, but Twilight was surprised they hadn't noticed anything wrong by now. Or perhaps they had, and they were just being polite while she went quietly mad.
"I was in my house, but it was like, made of ice cream? It wasn't really my house, either, just where I lived in the dream."
She would feel normal for a little while, but then she would see half an expression or catch hint of some faint scent or mishear a word and be struck by a memory that never happened. It was like watching her friends from behind one-way glass, she monitoring them silently in the dark.
"I had to swim through the walls to keep it from melting, or it'd drip all over Canterlot and I'd be arrested."
She couldn't tell them. Could she? How would she tell them? Excuse me girls, but I seem to have developed a series of one-way faux-relationships with all of you that happened completely in my own mind, so if I'm behaving a little unusual around you then that's why. It's nothing to worry about, unless of course I can't separate the memories of what actually happened from what I think happened, in which case I may be crazy. Pass the syrup, please?
"Why would you be arrested?" Pinkie asked. "That sounds super-teriffic. Superiffic!"
It wasn't really her fault that any of this had happened. She could tell her friends. They would be understanding, wouldn't they? It wasn't like this was the first time some bit of magic had gone wrong and done something unexpected. They could hardly hold her responsible.
Rainbow shrugged. "I dunno. Dream logic. Dreams don't have to make sense."
But what if it wasn't completely the fault of the spell? Twilight still wasn't completely sure what it did, exactly. Was it symbolic, or did it point to some hidden desire even she was unaware of? Or was it all garbage, nothing more than a idle what-if brought to life? Did the romantic overtones come from the magic, or herself?
"I thought dreams said something about the pony dreaming them," Fluttershy said. "Not that you're wrong, Rainbow. They don't always make sense."
What if somepony else used that spell and they experienced something completely different? Something mundane? Something straightforward? How could she even find another test subject that wasn't herself? The spell wasn't complex, but it did require some understanding of how to harness spoken magic, and a tremendous amount of force behind it.
"Yeah, that's what I heard too," Applejack said, "that dreams are subconscious whatevers, stuff you ain't ready to handle yet when you're awake."
She could always try the spell again, she supposed, even with the risk involved. But...
"What d' you think?"
...What if she had tried the spell again, and this was it? How could she tell? How could she ever tell?
"I said, what do you think, Twilight?"
Could she ever be sure that she was experiencing what she was experiencing, that it might not turn out to be--
"Twilight? Are you okay?"
Twilight blinked. "Yes," she said, and cleared her throat, "I'm fine. Just zoned out for a second there."
"Daydreams?" Rarity asked with a wry smile.
"Something like that." Twilight returned the smile.
She felt present at Sugarcube Corner in a way she had not since stepping inside, like the bakery was an anchor for her thoughts. Bedrock to rebuilt sanity. It was like remembering to breathe.
"Anyway," she continued, "while some dreams can reveal things about their dreamers, they're usually infrequent and require some kind of external method of recording, like a dream journal, to be analyzed in any great detail. The majority of dreams are fragments of memories assembled in a haphazard way by the sleeping mind. Mental noise, in other words."
"So..." Rainbow said, "does that make me right?"
"For most dreams. I'd say swimming through an ice cream house counts as just noise. Speaking of ice cream," Twilight said, coming to a realization as she spoke, "I'm still hungry. Do you girls want anything else to eat?"
"Ice cream?" Pinkie suggested.
"Not quite what I was thinking. Like pie, or something."
"For breakfast, Twilight?" Rarity asked with a raised eyebrow.
"Any time of the day is a good time for pie."
"Sure, I'm in," Applejack said.
"Me too," Fluttershy added.
"I could go for pie," Rainbow said, "as long as it's not blueberry."
"Blueberry?" Twilight said, as her mind threatened to double, buckle like heated wax. "What's wrong with blueberry?"
"Nothing's wrong with it, I'm allergic. Like, really allergic, my whole mouth gets a rash." She showed off her tongue to drive the point home. "It's gross."
When she was a little filly, Twilight would take her father's reading glasses to pretend she was grown up, as very smart ponies had glasses and naturally she would have them when she got older too. She would sit in her father's easy chair and read a book she had read easily hundreds of times before but secretly pretend to be deep in research for something very important and very complicated, and when she would be called for dinner, she would take the glasses off and be surprised every time when the world around her came back into focus. She had been adjusting to the lenses without knowing it, and taking them away made the room snap to attention. Every time she would think: This is what the world really looks like. I'd almost forgotten.
Rainbow saying she had allergies to blueberries, obliterating any possibility that for several weeks they had shared ritual slices of blueberry pie, made Twilight's mind snap to attention. She remembered the way the world really was, after almost having forgotten.
"Alright," she said with a smile that was only for her, "no blueberry."