That evening, they met up at the library. As always after somepony sent Princess Celestia a letter, they felt the need to meet, to repair any cracks in the foundations of their friendship, and to compare the lessons they had learned.
"Ah should've known that was the real you all along, Pinkie. You were the only sad one" said Applejack, throwing a foreleg over Pinkie's shoulders.
"But I didn't even know I was me!" replied the pink pony.
"And besides" interjected Rainbow Dash, who was just arriving. "you could've been one of the clones, and thought trying another emotion could be FUN!" On the last word, she raised her voice to mimic the shrill tones of the clones.
The conversation stopped for a moment. Nopony would've thought that such a philosophical idea could have come from the rough and tumble athlete. Rainbow blushed under the scrutiny. "What? I mean... It's possible right? Twilight?" She turned to the unicorn, the acknowledged brains of the group.
Twilight didn't respond right away, taking a drink of water. Then, she spoke.
"That thought crossed my mind. That's why I came up with the paint drying idea, and stressed that whoever failed the test would be banished back to the Mirror Pool. The clones just thought Ponyville was fun. Pinkie knew that the real fun was the ponies in Ponyville."
"Speaking of which, dah-ling" Rarity spoke up. "However did you keep from being distracted? I certainly couldn't have watched paint dry for two hours!"
"Really, Rarity?" Fluttershy asked. "I've seen you concentrate on one of your fashion projects for much longer than that"
Rarity waved a hoof at Fluttershy, dismissing her comment. "Oh, that was on a project, something with an actual goal. Watching paint dry is just...dull."
Pinkie spoke up then, with unusual seriousness. "There was a goal, Rarity. I thought I was me, because I could remember all our adventures. But I wasn't sure, because the clones might have had those memories. My goal was proving that I was the mare I remembered. The one that helped vanquish Nightmare Moon and Discord. The one that played the flugelhorn at the Crystal Fair. And the one who was friends with the best mares in Ponyville!"
The mares all smiled at that. They all loved their pink, energetic, party pony friend. And hearing oneself, and one's circle of friends called the best mares of anywhere was heartwarming.
Fluttershy spoke up again. The quiet pegasus had a knack for asking questions that made the askee really think.
"But Pinkie, how did you do it?"
She looked pensive for a moment. The others waited, respecting her need to gather thoughts that must be running wild with emotion.
"On your mark! Get set! Go!" Twilight yelled, waving her hoof for emphasis.
Instantly, Pinkie leaned forward. And so did all the other Pinkies. She was in real trouble now.
'I can't fail this test! I don't want to have to leave; and I don't want any of the clones to stay and have everypony think that's me. Yes, I like fun, but I like it when everypony else is having fun, too! I wouldn't have wreaked the Apple family's barn, or woken Dashie up from her nap, or pulled any mean pranks!'
From somewhere, she heard a shrill voice – was that really how she sounded to other ponies? - say something about a birdy. She almost turned to look, but a certain blob of paint caught her eye. It looked like... looked like... a baby's diaper?!
'Of course! Pumpkin and Pound Cake! If I fail, I won't see them anymore either! I wonder...' Her eyes roamed over the canvas, an idea forming in her mind. Yes! The blob looked like the royal carriage Twilight first rode into Ponyville! And that one looked like Spike wearing a lampshade at the first party Pinkie had arranged at the library!
Slowly, Pinkie went over all the adventures she'd had with these dear friends over the past two years. Then, she expanded her search. There was Cranky Doodle, and right beside him was Matilda. Together forever, they were. There was the quiet pony who worked at the bookshop. She would smile, but there was always something scared about her, too. There were the Blossom triplets - Daisy, Lily and Rose. Their gardens always won the Beautiful Ponyville contest. And the Edible Ponyville one, too. One by one, Pinkie found everypony in Ponyville, from Twilight and the rest of her closest friends, to ponies that she'd only met a few times, but liked anyway, like the mining pony who always flirted with her when he came into SugarCube Corner for pastries. He'd buy enough for his whole crew, then leave one behind "for a pretty pink pony. Know of any?"
"Pinkie! You can look away now!" Twilight's voice broke into her thoughts, interrupting her search for a paint blob that looked like the violet unicorn she'd seen at the Grand Galloping Gala, and again in the crowd at Princess Cadance and Shining Armor's wedding. She looked around. Other than Fluttershy's mane, there was one source of pink in the room.
"I passed?"
"That big canvas you made us all watch," Pinkie said slowly. "I remembered everything we've done, everypony I've ever met. And I knew I'd have to give them all up if I failed. So I looked for paint blobs that reminded me of everything."
Twilight looked thoughtful for a moment. "There's a pony psycology writer who theorizes that what makes a pony a pony is what she's done,and what she's going to do. I guess you proved her right"
"Which makes this an appropriate gift!" Rarity cheered, as she pulled a sheet off the wall. Behind it was the now dry canvas.
They all laughed, tension gone. After a moment, Pinkie spoke.
"So,who wants to help me get it home?"