Spike looked up from his breakfast when he heard one of the main doors to the dining room slowly swing open. He stared for ten seconds before the first glimpse of Twilight Sparkle entered the room, on account of her turtle-like pace.
She looked tired, although she had denied feeling it. Rather, she claimed that she didn't feel motivated to do anything, and she wasn't the only one baffled by that. Spike had known Twilight Sparkle long enough to know that she tended to get more motivated when she encountered a problem, and could work herself into a tizzy if it proved challenging enough to resolve. While she was still new to being the princess of Equestria, she had been adjusting to it just fine, and had been determined to do a good job, so that didn't appear to be the issue.
Magical examinations had found no spell cast upon her, a physician had concluded that she was perfectly healthy, and a visit to a therapist hadn't solved the mystery either. The only potential clue that they had to work with was that she felt as if something might be missing, but all attempts to fill that unknown void over the past two weeks had born no fruit: visits from friends, reading new books of interest, and taking a break from her responsibilities.
When Twilight Sparkle finally reached the table, she turned to regard Spike and said, "Morning, Spike."
"Good morning, Twilight," he replied, as he looked at her with concern. "Still feeling out of it?"
Twilight Sparkle sighed. "Worse. All the effort required to take care of my obligations is starting to wear me down."
"Maybe you should take an entire day off to relax," Spike helpfully suggested.
"I don't know..." Twilight Sparkle replied, as she mulled it over. "Ponies are already beginning to think that I'm slacking off."
Spike frowned as he watched her climb onto her chair. Once she was seated, several ponies rushed into the room and served her breakfast. While that was happening, he wondered if anyone would ever figure out what was wrong. He hoped that Rarity would have an idea, who would be arriving at Canterlot sometime that morning. If nothing else, she would know how to get Twilight Sparkle the rest that she needed.
"You look absolutely dreadful, darling!" Rarity exclaimed from beside Spike, upon seeing her friend for the first time since hearing about her condition.
Twilight Sparkle was slowly descending the steps before her throne, having just recently finished conducting the last of that day's business. She looked confused as she replied, "But I've been having professional ponies attending to my appearance lately, so I'm not late tending to any of my responsibilities."
Rarity shook her head. "I'm not talking about the superficial part of your appearance." She proceeded to dramatically declare, "I'm referring to your bearing! Your countenance! Your aura!" Her expression grave, she jabbed a hoof at Twilight Sparkle and delivered her prognosis. "Dear, you've got a serious case of the doldrums!"
Both Twilight Sparkle and Spike blinked their eyes bemusedly and repeated, "Doldrums?"
Nodding her head with certainty, Rarity said, "That's right. And when I have the doldrums, I like to have a little 'me time.' So, that's what you're going to do."
"I've already tried taking a break, though," Twilight Sparkle informed her.
Rarity scoffed. "Darling, 'me time' is no mere break. It is a sacred ceremony devoted to the revival of oneself, like how we perform tasks specific to each season to bring them back every nine months."
"I don't know..." Twilight Sparkle responded, her brow furrowed. "I'm pretty sure I've done everything that I enjoy doing over the past few weeks."
"Obviously not," Rarity disagreed, frowning thoughtfully.
Spike spoke up and proposed, "Hey, how about we compile a list of everything you've done so far? That way we might notice if something is missing."
"That's a wonderful idea, Spike!" Rarity praised, making the young dragon blush. She returned her attention to Twilight Sparkle and ordered, "Let's retire to your room and suss out this elusive activity."
Twilight Sparkle complied, since she was out of ideas and had nothing to lose but some time.
It took them a while to reach Twilight Sparkle's room, due to the owner's pace and Rarity's unwillingness to carry her and make her look undignified. As soon as they entered, Spike went to a desk, where quill, ink and parchment were available, and sat there, ready to jot down whatever was dictated to him. Seeing this, Twilight Sparkle began to recount her activities for the past few weeks, with Rarity and Spike asking about one if it hadn't been mentioned yet, whenever the silence grew too long.
After a while, Rarity began to notice that Twilight Sparkle had become more lively than she had been earlier, and with more scrutiny noticed further improvement as time passed. Eventually, when it seemed that she had returned to a state of normalcy, she decided to interrupt their current venture.
"Twilight," she interjected, breaking said pony out of her thoughts, "have you noticed anything different about yourself?"
Twilight Sparkle stopped pacing and tilted her head. "What do you mean?"
"Aren't you feeling better?" Rarity patiently pointed out.
After taking a mental inventory of herself, which included the lifting of one forehoof after the other, then raising each wing and giving them a flap in turn, Twilight Sparkle exclaimed, "I am!?"
Confused, Spike asked, "How, though?"
Rarity stroked her chin as she peered at her reinvigorated friend. "If I had to guess... I'd say it was from making a list."
Silence descended upon the room as that idea sunk in.
The silence was finally broken when Spike turned his judging gaze toward Twilight Sparkle and remarked, "Seriously?"
Smiling sheepishly, Twilight Sparkle rubbed the back of her head and responded, "Well, a lot of things do get relegated to other ponies..."
Shaking her head with some exasperation, Rarity said, "Darling, only you could feel listless when you're listless."
Word of the princess' recovery spread far and wide, and henceforth she would unofficially be known as the Princess of Lists. One day the naughty and nice lists would become a part of her legacy, but that's a (very unlikely to be written) story for another day.