The good thing about having a secretary was that you told them what you wanted your voice to be, and they gave it to you. That was the relationship of Princess Celestia and Raven. Any time something generally unimportant was to be written, Celestia no longer needed to even dictate what it was. Raven would draft up a reply, type-written and clean. Princess Celestia would give it a once-over to ensure it was what she wanted ‘her’ words to be, and then add a royal signature and her Eternal Crown seal. After everything was finished, magic would whisk away the letters.
Faithful Students and a few others and occasions aside, Princess Celestia used this assembly line of letter-writing for many centuries. It pared away enough of who she never wanted to be and let her craft a costume of tone and scarf of diction fit for every occasion. Most importantly, it saved her time and was a blessing to the all-important schedule. Without such a process, her life would not have a vitally mechanical element.
Writing to Sunset Shimmer was not something that could be done with that method. There was nothing about that which didn’t frustrate the princess terribly. She wanted this to be easy and manageable. She always wanted things to be that way and for clocks to run backward to give her enough time to try and figure out something about tweens that made sense. If that were possible, then Princess Celestia would strip life of dreams and nightmares so that calm reality could take its place. There would be no sorcery problems, mirror-worlds, unreachable moon-prisons, and nopony would ever have to hurt again.
Especially Sunset Shimmer. Goodness, if she could have spared herself the hurt of losing her constant, her Faithful Student, no matter the difficulty brought by Sunset’s… colorful personality.
Princess Celestia flipped open her book with the delicacy and revulsion of somepony trying brain surgery on a dear friend. She still smelled the staleness of the dust that clung to it, and the unpolished state of her cutie mark upon the cover was a silent reminder of the times when she had scribbled various orders, curriculum-related and otherwise for her Faithful Student. Most had been about all the things that Celestia couldn’t do: how she could not forgo court for personal lectures she never gave past Faithful Students when their textbooks were just what they needed, why curfew was important for growing fillies, and the importance of holiday event attendance by the nation’s princess.
Each of those lines was still there, their ink long since dried and the hornwriting as immaculate as ever. The sight of them only made a fissure of regret tug at Princess Celestia’s throat, demanding she takes a swallow more fitting for somepony on the verge of sobbing. How was she to address a mare who was all-grown-up in a world neither of them had any understanding of? What is the proper way to talk to someone who one can't find and doesn't want to be found? When it came to the factor of Sunset having possibly lost or thrown away her half of the communication journal, what was Princess Celestia supposed to consider the most likely option? That Sunset still retained the item she had once seen as both a magical marvel and annoying hobble of an agenda?
She thought of everything she wanted to say to Sunset Shimmer and pressed her quill to the page.
She was ready to write.
All she had to do was think of how to say a tiny watered-down fraction of everything she had dealt with in the years since Sunset left. That would be a good start.
What came out were dribbles of ink, and nothing more.