Celestia had many titles. Princess of Equestria, Sol Invicta, Bastion of Light, Liberator of this and that. Today, however, it was Birthday Mare.

She slipped quietly into the hallway outside of the royal guest suite, which had been redecorated for the occasion. Talking and merriment could still be heard drifting from under the door, it would be a few minutes until someone noticed her absence. That's all the time she needed.

She walked down the carpeted hall, slowly but purposefully, toward the end where a lone lantern illuminated the Kitchen of Two Sisters. The castle staff cooked for them most days, but they had this smaller kitchen for the occasion that either sister wanted to cook for themselves.

Alone in the kitchen sat a pink pony, nose buried in a book but ears perked. She had respectfully ducked out after the party started, but happened to show up periodically when something was needed.

Celestia cleared her throat, rousing Pinkie from her reading. Her cheeks dusted a deeper pink color as she set the book down. It was about carbon dating.

At Celestia's inquisitive glance, she giggled and rubbed the back of her neck.

"Don't tell Twilight or my sister, but I've kept reading stuff even after. It's fascinating stuff."

"I'm sure. Not going to use it for anything nefarious this time, are you?"

Pinkie shook her head.

"I just wanted to thank you, away from everypony else. Despite your methods being questionable, though cunning, I do really appreciate what you've done for me."

"I told you that I'm a professional! I even managed to sync up with Princess Cadence and Shining Armor's schedule, making sure they set aside the time for a visit." Pinkie beamed.

"Yes but it's more than that." She moved around the island counter toward Pinkie. "You took something harmless, something inconsequential, and used it as an opportunity to make another pony smile. Moreso, you've done it twice."

"Oh! You mean my, uh, dictionary word thing. Yeah it's fun for me, but I didn't go into it with the intention of making it some big deep activity."

She brushed up behind Pinkie.

"Maybe the first time, with the pancakes. But this was something else entirely. Weeks of research, countless hours of time each day. All devoted to what is essentially a bit."

"You all know me!" Pinkie stuttered a little. "I'm quite a silly pony. And like Granny Pie used to say, if you can do something, you can do it right. And like Rarity has said, sometimes moderation is best practiced in moderation. Why shouldn't I have gone overboard with it?"

"Why indeed." She spun the chair around that Pinkie was sitting in so they faced each other. "While you did attempt to embarrass me in front of a hoof-full of the castle staff, it pains me to admit that they've witnesses worse. Yet that does not change the effects of your actions. Only you would take an innocuous task and make the conscious decision to go overboard for the sake of somepony else like this. Because that's who you are. You make ponies smile, if in a convoluded and roundabout way at times."

Celestia sat on the floor, which put them at a more even level with each other, if only a little.

"Luna was like that in our youth. As much as she was a jokester, she was deeply caring for others. She would wander the streets spreading joy. And she used to have a habit of crashing weddings, but as the officiant if you can believe it. It's why she was so hurt when ponies started shunning her and her night. She left so... underappreciated."

Pinkie's eyes were wide as Celestia bent her head down until she was at eye level with the smaller pony.

"You're so very much alike, you know. Deceptively intelligent, endlessly kind, devious in the best way.

So, I want to tell you this, one on one, that I appreciate you and all that you do. For your friends, for the ponies of Equestria, and for what you've done for me today."

Celestia pulled her to her chest, enveloping her in her legs and both large white wings. It was, quite likely, the most comfortable hug in all of Equestria.

"Thank you, Pinkie Pie."

Pinkie gingerly returned the embrace, then firmly. Her form, completely enveloped in warmth, shook and shivered. Once or twice, a muted sob emerged from within the cocoon.

The hug ended a short eternity later, but Celestia kept her wings up around them as Pinkie wiped at her eyes. Her ears flicked toward the doorway.

"Princess? Are you in here? I didn't see you leave the party."

As Twilight trotted into view, Celestia quickly grabbed a stack of napkins in her magic, keeping Pinkie shielded with a wing.

"I am here, Twilight. I stepped out for a moment to retrieve some napkins. I'm afraid I gave your friend here quite a spook. You know how silent I can walk on these carpets if I'm not paying attention."

Twilight cast a furtive glance around the kitchen. "Oh, ok. Well come on back, Cadence wants to play pin the tail on the pony with Flurry, and Luna said you'd be happy to volunteer yourself since you have the... um... biggest..." She trailed off, Luna's reasoning now dawning on her.

Celestia waved off her concern and laughed lightly. "I'll be along in a moment. And please, call me Celestia. You're a princess too, remember."

Twilight blushed and nodded, backing out of the kitchen. The odds of her breaking that particular habit were very small.

A sniffle to Celestia's side drew her gaze back to Pinkie, who had mostly gotten her face cleaned up from her emotional moment. She mouthed a silent 'thank you' since Twilight was still relatively within earshot.

"Go get some rest, Pinkie. I think we can manage just fine for the rest of the party." Pinkie made to argue but Celestia cut her off. "I imagine being a party planner on the side is quite tiring." She gave her a mischievous wink. "One might say, it's arduous work!"

Pinkie wasn't sure why she put so much emphasis on the word, but agreed nonetheless.

As Celestia rejoined the party, napkins held aloft in her magic, she took a moment to survey her little family. Everyone she loved in one place for the day. Tax Filing Day might just become her favorite day out of the year, now.

And as Pinkie laid in bed, she flipped to her current page in the dictionary to give herself a head start on the next word. She nearly cried out at what she saw.

Arduous, adjective, involving or requiring strenuous effort.

Clever Princess.

Author's Note

Allo!

This is bug. Fate schemes for my downfall, yet I persist.

This fic brainwormed me from the moment I wrote, "I’m gonna try to use archaeomagnetism in a sentence.” It was intended to be a silly throwaway line showing that Pinkie wasn't finished with her antics, and the word itself was chosen because it a) came after arbitrary in the dictionary and b) sounds hopelessly complex for Pinkie to ever have a hope of using.

But here we are anyway!

Hope everyone who read this enjoyed it. And if you did, feel free to leave a comment. They are an author's chips and dip.