Dear Princess Celestia,
My friend Applejack is the best friend a pony could ever have, and she's always there to help anypony. The only trouble is, when she needs help she finds it hard to accept it. So while friendship is about giving of ourselves to friends, it's also about accepting what our friends have to offer.
Your faithful student,
The immortal co-ruler of the land of Equestria smiled slightly as she read the report; the smile evolving into a chuckle as she read the accompanying pages which gave the details of how the lesson was learned. She briefly considered creating a few “Baked Bads” of her own to sneak into the next boring high society dinner she would be forced to attend. The sheer violence of the townsponies' reactions quickly squashed that idea, though she made a mental note to coerce one of the royal bakers to sneak some chili powder into one batch of desserts next time nonetheless.
These letters from her most recent, and—if she were to be completely honest with herself—favorite protegee were sure to become a high point in the regal white alicorn's week. The young unicorn was a rarity in Equestria, able to write the Eternal Sun Princess in a way that was conversational, friendly, and warm. Her letters tended to be completely devoid of pomp and circumstance and even Twilight's own “devoted student” nervousness. Though Celestia had always managed to maintain a close friendship with at least a couple of ponies in any given generation, such ponies were proving increasingly more rare as time passed, and Princess Celestia cherished each and every one. She rolled up the scroll as her thoughts turned to concerns even closer to her heart.
Celestia sighed softly as she looked around her personal quarters—much more homey than most ponies would consider for their wise and beloved ruler, with high quality but simple décor and a warm and inviting fireplace. The last few weeks were some of the happiest in recent memory. After one thousand years her precious little sister Luna had finally been returned to her, and their relationship had begun the slow recovery process. And yet, Celestia was becoming concerned. Luna had always been serious and introverted, but since her return had essentially become a recluse; only leaving her room to perform her moon-guiding duties, meals, and the odd “family bonding” time with Celestia herself. She was behaving much as Twilight Sparkle herself did prior to being sent to Ponyville specifically on assignment to make friends. Remembering the consequences from the last time Luna lacked in interpony relations, one would be hard-pressed to blame the older sister for concern. Celestia decided it was time to chat with her sister after she set the sun in an hour.
Silence reigned as the other immortal princess worked on her latest project, the only sound the clicking of small beads clacking against each other. Her personal quarters were similar to her sister's in that the décor was elegant yet simple—if darker and less warmly inviting. However where Celestia's quarters were almost immaculately clean, Luna's walls could barely be seen behind the sketches, paintings, and drawings pinned almost haphazardly on almost every square hoof of her walls. The midnight blue alicorn herself sat at her paradoxically organized desk, a book open in front of her to her left, a piece of paper directly in front of her rapidly being filled with notes written by a magically controlled quill, and an old abacus floating above her head. She was so absorbed in her work she didn't hear the knock on her door, nor the door opening, nor the first three times her name was called. It wasn't until the fourth, vaguely exasperated “LULU!” that she spun around in surprise, nearly falling out of her chair in the process.
“Oh, Tia. Greetings,” Luna sheepishly said, using a pet name for her sister that she would never speak outside of the absolute privacy of their own chambers.
Celestia grinned a bit at her younger sister. Luna had only been free for a few weeks, so she had yet to show any signs of her true near godly power returning, her curled blue mane just barely sparkling a bit under the right lighting conditions. “You were doing it again.” The grin increased ever so slightly. Luna and Twilight Sparkle were very similar in their ability to lose themselves in a project.
Luna could not help but blush a little. “We... apologize. We simply desire to return to our full capacity as soon as possible.”
Celestia smirked. She had of course told Luna that the “Royal We” was no longer used in modern speech, but where Celestia lived through the gradual change in linguistics, Luna, well, hadn't. And Celestia suspected that, like the scratched and worn abacus, falling into the old speech pattern was something of a comfort mechanism. “And I've always loved you for your dedication, little sister. And yet I worry that you might be dedicating yourself to your work to the exclusion of other equally important things.”
Luna raised an eyebrow. “Such as...?”
Celestia's smirk grew wry, and Luna became somewhat petulant. “We do not have the need nor the time to engage in social activities at this moment,” she huffed.
“You sound exactly like a certain young mare I know,” Celestia replied, then chuckled. “Well, not exactly...” she stifled her laughter a bit at her sister's glare and passed her the letter she had read an hour previous. “In any event, look at how far she's come in a few short weeks.”
Luna read the letter, fully understanding Celestia's mild reproach due to her own stubborn need to return to her duties on her own terms. “...It is a worthy lesson for anypony to learn. Even princesses,” she admitted ruefully. “And yet we are curious. What is the point of her writing like this? It reads almost as if it were... a school assignment.”
“In truth, my student is almost woefully inexperienced at making and keeping friends. You might not believe it, but she met her friends just earlier the day of Nightmare Moon's attack. And at this point, they are her only friends.” Luna gave Celestia a clear look of disbelief, which the older sister quite enjoyed. “It's true. Though, that group of mares is rather exceptional. The assignment was given mostly to help ease her into a different sort of life than she's lived up to this point. She's always been a studious sort, much like you.” Celestia softened her gaze, then leaned in and nuzzled her sister. “I won't force anything on you. It's a difficult transition for the both of us, and I only wish the best for you. And I feel making a friend besides me would be an immense boon. Part of the, ah, problem before was that you felt alone. Will you at least try to meet and befriend somepony?”
Luna hesitated. “We... I am not entirely sure how to, to befriend anypony. I do not believe I really had one even before th-the Nightmare.”
Celestia blinked. “None?” She almost could not believe what she was hearing. Luna, ever the artist, trying to make the night sky perfect. Luna with a laugh that could melt hearts if she'd let it out now and then. Luna, who was if anything more of an incorrigible prankster than Celestia herself if you could get her started. Luna had never had a friend? “Oh, Luna... I'm sorry.”
Luna flashed a look of irritation at her sister. “As I have already assured thee, apologies are unnecessary. 'Twas I that...”
“No, Luna. I think I do owe you an apology, and more. I've long thought that I somehow missed something important through negligence... and now I know I did. No friends outside of me? Ever?”
Luna looked thoughtful for a moment, then sighed and changed her story. She could never really lie to Celestia. Not for long at least. “In truth, I did have one. Or two. But, but time passed and, and so did they." Luna dropped her head at the memory. "And... and it hurt, and I did not wish to feel that again.”
Celestia stopped short. She herself had dealt with the same pain many times over the ages, but knew that the good times beforehand were more than worth it. It... somehow did not occur to her that her sister, who already had a harder time connecting with other ponies, would feel that pain and conclude it better to avoid it in the future. “It was that first time you threw yourself so entirely into the night sky... like tonight. Wasn't it?”
Luna simply gave a nod, and Celestia understood. That first night was some centuries before Nightmare Moon—a long time for ponies in general, but not an especially long time for the princesses. Luna's need for companionship and appreciation would have conflicted with her avoidance of the same and would have eventually unbalanced her enough for the Nightmare to take over.
“Oh Luna...” For the first time in a long time, Princess Celestia could think of nothing to say. Luna, however, nuzzled her sister.
“We shall be all right, sister,” the smaller princess murmured. “We have had much time to reflect upon our mistakes. Including sacrificing the Magic of Friendship to avoid pain. We, ah, I will endeavor to take your own lessons to heart. Perhaps if you could continue to share your student's lessons with me?”
Celestia had to struggle to not let her voice crack. “Of course, sister. I... good night, Luna. We'll discuss this more tomorrow.”
Luna gave her sister the bravest smile she could muster and nodded understandingly. As Celestia left her to her privacy, Luna attempted to get back to her project, but though her abacus clicked away, no actual calculations were being done in the Moon Princess's head.
Once outside Luna's quarters, Celestia had returned to full “Regal Mode.” Centuries of practice would ensure that only the very, very few members of the staff who truly knew her personally would even guess at something being wrong.
“Excuse, me... Princess...” a somewhat intimidated sounding female voice asked, actually startling her somewhat. “Is everything alright with your sister?”
Celestia turned and regarded the little green earth pony in servant's attire before her. Her Cutie Mark was an image of a bottle of medicine behind a heaping spoon of sugar. If Celestia's memory served, her name was Sugar Heart. “Why would you ask that, dear?” she asked.
Sugar Heart shuffled nervously with the Princess's attention turned directly on her. She took a deep breath as she began speaking. Rapidly. “Well I know Princess Luna has not been back long and she has been hard at work in her quarters practically since she returned and the other servants tell me it's none of my business...” she stopped for breath. “But when she first got here she was so excited to be working on the night sky again she'd make these little hmm's and aaah's as she worked and ideas would come to her and she'd show the constellation sketches to anypony who'd be within reach—me often as I have been assigned her personal servant.” The mare chuckled a little bit, now unaware of the appraising look the Princess of the Sun was giving her. As she continued, she spoke considerably slower and more controlled. “Reminds me of my older brother a bit. He's an artist, too—so childlike when inspiration strikes. But the last day or two, she's been... silent. Just working at her desk with that... bead thing clicking away. It's so different from before, and I know I'm just a servant and everything and I may be completely out of line asking but I'm just kind of worried about her and I miss the hmm's and the aaaah's and I just want to make sure everything's okay.”
Princess Celestia smiled down at her little pony, amused a bit at the nervous rush of words she tended to exude, but more impressed at the courage and kindness of the little pony in front of her. As Sugar Heart herself had intimated, the staff largely tried to simply blend into the background and performed their jobs, rarely saying more than the absolute necessary to the princesses themselves. This concern she was showing for her sister was above and beyond the requirements of the station, and the fact she had mustered the courage to inquire Celestia about it spoke volumes. It was almost exclusively through the efforts of the other five mares that Twilight learned of the Magic of Friendship. Could Celestia hope that fate was kind enough to maybe give Luna an equally impressive friend? Celestia decided that she could. “I think Luna will be fine.” She gave a smile to the little pony before her. “It will take time, and understanding, and patience. But I think she'll be fine.” Celestia leaned down and whispered somewhat conspiratorially with the now somewhat confused servant. “I also think you should ask her yourself. She may not seem the type but she really would appreciate it. And don't get frightened if she shouts the response back. Old habits do tend to die hard.”