Billions of years passed.
During this time, Grasping Hand and Moving Finger’s species also died, and joined the fossil record, just a few layers up from their beloved dragons and ponies. The light of sapience disappeared from the world once more.
It did not return.
Let’s talk about Boulder.
After Grasping Hand died, Boulder was inherited by one of her daughters. She didn’t know why Boulder was important to her, for she was never told, but she knew how important Boulder had been, since Grasping Hand had insisted Boulder be next to her when she died. So she kept Boulder in the same cabinet as her photo albums and participation trophies. Occasionally, she would look at the chunk of basalt and smile, as a picture of her late mother filled her head.
After Grasping Hand’s daughter died, Boulder went to a landfill.
Not much happened after that, from Boulder’s perspective, until at some point a set of meteors made impact on the planet. The first was large enough to burn away the atmosphere. The second impacted at just the right angle to launch Boulder, and a whole lot of other matter, out into space at escape velocity.
The escape velocity of the solar system, that is.
With a trajectory perpendicular to the plane of the galactic disk itself, Boulder’s voyage into the intergalactic void was predictable. As was his fate. With hardly a particle to cross his path in that lonely darkness, Boulder would just continue to be, throughout the countless eons. Long past the billions of years it would take for the star Celestia once raised to expand, swallow the planet She once walked, and die. Long after the last sapient interstellar civilizations, desperately clinging to life around the last of the black holes, vanished. Long after that.
Luckily, Boulder is just a rock, so that doesn’t really mean anything.
Let’s talk about magic.
At one point, the planet Equestria was on teemed with it. It not only gave life to the fantastic creatures way too high on the trophic system to be sustainable in their environments, but also sapience to the dozens of species we are familiar with today. What else could explain these myriad species from different evolutionary lines developing cultures and civilizations and mindsets more compatible than those of a single culture separated by fifty years in time?
Of course, that is not all. Folks say the Everfree Forest doesn’t work the same as the rest of Equestria. It’s not natural. The animals care for themselves on their own. Thanks to the powerful magic of the Everfree, they have sapience, though they lack both a material culture and the ability to speak Ponish. From the bears to the squirrels, from the rabbits to the bees. Even non-living constructs made of wood and leaves. This tells us something.
The sapience that magic endows doesn’t need neurons.
So why not a rock?
Let’s suppose, as a hypothetical, that Boulder was sapient, and consider his long journey into eternity.
To us, this fate would be straight out of a tale of cosmic horror. Countless eons of not even the hope of external stimuli. There is a reason solitary confinement is considered torture.
But Boulder is not us. Boulder does not feel ennui or boredom or existential malaise. Do not be sad for Boulder. Boulder is content. Boulder has his memories.
Sometimes, Boulder thinks of Grasping Hand or her daughter. He tried his best to communicate with them, but the magic was so weak by then. He could only project vague feelings, so weakly that the effects would be indistinguishable from invoking an emotional association. But he did his best to pick that vague feeling well, to bring as much comfort as he could, because he is a good Boulder.
Sometimes, Boulder thinks of Starlight’s life after Maud. Boulder never did try to talk to Starlight like he did to Maud, though he could have. He didn’t want to distress her. She talked to him all the same. Mostly about Maud. He liked hearing about Maud.
But there was always a pall of sadness over that period of Starlight’s life. She never stopped grieving her, all the way up to the end. Her subsequent partners understood, or left because they could not. She never found the happiness she had with Maud again, but she never regretted that either. Once in a lifetime was a miracle enough.
So mostly, Boulder thinks of Maud. The mare who grew up different than other ponies, on an isolated rock farm. The mare who had no friends and, though she loved her sister, could not understand or be understood by her. The mare who was lonely enough to begin talking to a chunk of magnesium-rich basalt she found on one dark and stormy night. For hours and hours throughout the years, providing the magic-powered matrix of computation inhabiting Boulder the raw material it needed to turn into language and consciousness.
That is to say, mostly, Boulder thinks of his mother.
Of course, when he thinks of the first part of Maud’s life, he also thinks of her loneliness. A pall of sadness, the mirror image of Starlight’s. As meaningful as Boulder was to Maud, he knew Maud needed something more. Somepony to love her, to understand her, and to be understood and loved by her. Maud tried her best to be stoic about it, but Boulder could still hear the sadness under her monotone voice. So he was very glad when Maud found that somepony, and happiness, at last.
So really, what Boulder thinks about the most during those long eons are the last years of Maud’s life. The ones she spent with Starlight Glimmer.
In his mind, she is still reading her latest poem about rocks as Starlight gazes up at her in awe, chin resting on hooves.
In his mind, she is still kissing her as Starlight holds her hooves, trying to distract her from giving her lesson about an obscure kite technique.
In his mind, she is still saying “I do” in a quiet ceremony in front of the Castle of Friendship, where they met for the second time in their lives.
In his mind, she is still lying on that deathbed, even her eyelids immobilized by the progression of the disease, but her mind still sharp. Still able to gaze into Starlight’s eyes through the caps of clear saline. Still determined to have those eyes be the last thing she ever sees. Still alive.
In his mind, she never really died. That is the closest we ever get to immortality.
But that hypothetical is silly, right? Boulder is probably just a rock.