Looking out across the ocean at the red sun hanging high above the sky, Luna recalled.
She recalled her first waking moments on the strange planet that had no name.
She recalled the thousands of years of happiness and joy with her dear sister, the love they shared and the games they played. They'd meant so much to each other, an inseparable bond not broken by responsibility, indifference, jealousy, or even death.
She recalled the centuries of war and strife, of darkness and fear, and of hopelessness. The times when the sun had abandoned it's humble subjects to the cold despair of the night. The times when blood was spilled and tears were shed, times when civilizations rose and fell and the earth shook with the brute force of a war undesired by both sides.
She recalled every mortal pony who bowed to her and every one that rightfully opposed her during those dark years. Everypony she'd ever known, she had watched live and die while she remained unchanged. Across the long stretches of time when even the gods and Queens died, only Luna and the sunny skies of Equestria remained unaffected. But even now, like the sun was cooling and the light of the earth was dimming again, Luna was no longer the spry young alicorn she once was. Her flowing, starlit mane was still largely the dark blue it always had been, but it was also tinted with traces of purple and yellow around it's edges, a trait reminiscent of the mane of her sister. Now though, even it was beginning to grey with age.
She recalled Queen Chrysalis and Nightmare Moon, two friendship's she never would have imagined making. The brusque changeling Queen who kept her kind heart hidden behind her pride and selfishness, and the black alicorn who lived and died seeing herself as a monster and never realizing how wrong she had been. Both of them had taught Luna so much and helped her in ways she or they could never have imagined. She had first seen Chrysalis when she was a mere two decades, an arrogant and overconfident mare just out of fillyhood, but she had watched her grow into an elderly changeling of three thousand years. She had been so frail, her wings tattered, no more than a jagged bump on her forehead where her spiked horn had once been. Luna had visited her one last time, and learned that several days later she passed quietly with her daughter by her side.
She recalled the Elements of Harmony, Twilight Sparkle, Pinkie Pie, Rarity, Applejack, Fluttershy, and Rainbow Dash. Heroes of their time now lost to the sands of tens of thousands of years past. Their children's children's children's children had passed half of a dozen millenniums ago, so that even the language they had spoken existed only as a memory in Luna's mind.
Most often, when she looked at the orange night sky and the red sky of day, she recalled Celestia. Her beloved sister, sustained in her memory forever as the good mare she'd known her as. The passing of time had rendered nearly ever mortal life a grain of sand in an ocean far too wide for a pony to sail even in a thousand years time, but the vivid clarity of those who had been close to her had never faltered with time. Once upon a time when she rested, her sister would join her in her dreams like she was really still alive, but when Luna awoke, the truth always dawned and hurt much more as she realized that it had been a mere dream. Eventually, Celestia stopped appearing in her dreams all together, which was probably for the better. Luna didn't dream after that, and even when she slept, the morning crept past the span of time like it had not existed at all.
As the poor old sun had slowly lost it's luminosity over the centuries, so too did Luna feel the end of her lifespan slowly creeping up on her. The unicorns had been raising her sun and moon for millenniums, and it was with comfort that she knew they did not need her anymore.
Luna felt tired and weary. When she closed her eyes, she felt as though if she wished, she could fall asleep and never awaken again. With nothing left and nopony she cared about alive, Luna simply recalled. It was her favorite thing to do, as she waited for the end. In a hundred years or so, she imagined the time would finally be upon her to die and she would close her eyes on her world one last time.
And it wasn't with fear that she thought of this looming guarantee. In fact, it was quite the contrary. She had lived long and, like her sister had requested thousands of years ago, she had found happiness again. There was always sorrow and longing looming behind the happiness, always the desire to see her loved ones again, and it was this desire that now kept her looking forwards with the hopeful optimism a young filly might have on Hearth's Warming Eve. For her, having lived so long, it felt like the same pathetically small yet unbearably long time interval.
For hundreds of years she had simply walked her earth, smiling up at the sun, revisiting all the places that had meant so much in her past life. She walked the boardwalk of Dusk Falls that was now nothing more than sand as red as blood, she crossed oceans that were now deserts or deep, waterless craters in the ground like sinkholes descending into darkness. The beautiful city of Canterlot, the peaceful silence of Ponyville, all civilizations come to dust in all but her memory.
She'd brought about peace. She'd ruled for many years and she had been happy during them. Now, her mane was grey and her eyes felt heavy with the strains of a billion lives, but the sun gave her comfort and warmth and made everything seem trivial and distant. Looking back at the almost twenty thousand years of life she had lived, she couldn't help but smile at the satisfaction of having it all behind her.
In many ways, the unknown future was all she had left. But it would be enough.