It all started with the end of the world. Well, more precisely one could say it began with the beginning of the world, but the beginning began with the end, which in turn started at another beginning that was triggered by yet another end. So I suppose we'll just have to settle for saying it began with the beginning of the thing that first began to trigger the beginning of the end that would begin the world again.
So by that logic, It all began with a bag of oatmeal, being held by a particular pink pony in a pastel town by the particularly apt name of Ponyville. In actuality, it was one particular piece of oatmeal that began the mess, located in the mathematical center of the small leather bag (more of a sack really). For the sake of simplicity we shall say it was the bag and continue.
The pastel pink pony, one Pinkamena Diane Pie, was exercising her many talents in the stunningly ordinary task of baking oatmeal cookies, with delicious chocolate chips and inordinate amounts of sugar. She was not exercising her talents in the act of baking (although an excellent baker she was), nor in the party she was baking for (although she was undeniably excellent at those as well), but in the extraordinary way she went about the menial task.
For starters, she was performing an astonishing amount of tasks at once by making use of the extra hooves that seemed to have come out of nowhere. This allowed her to perform every step necessary to bake exemplary cookies at once, from preheating the oven to washing her hooves (which she was somehow washing and using simultaneously) to mixing the ingredients, which, like her hooves, seemed to spring out of nothingness.
As she went about her task, she narrated everything she did aloud with fervor as though she expected someone was watching her, even though no other pony was at the bakery and she had no reason to believe that any sort of audience had gathered to observe her. The mare bounced about excitedly as she worked, exhibiting an astounding amount of energy for a small equine creature.
"And now we have to get the ingredients to make some delicious cookies for our friends!" Her voice was as bouncy as her movements. "We'll need a cup of flour for the mix, and of course some sweet chocolate chips to bake in. Now some ponies like to use raisins in their cookies, but I have no idea why anyone would do that, There's these perfectly good chocolate chips and those silly fillies want to use raisins, I mean can you believe it!" Each time she mentioned an ingredient, she pulled it out of thin air and held it up for whoever she believed was watching to see. "Whoops! I almost forgot the oatmeal!"
As with the other ingredients she reached her hoof into an empty space and pulled out the desired object. But this time, there was something left behind. More accurately, this time it left nothing behind. Where the bag of oatmeal used to be, there was something that could only be described as a hole in the air. Not so much that there was no longer air there (although there wasn't) but that there was nothing there.
Pinkie Pie stopped and stared, having been, for the first time in her life left completely speechless, and completely at a loss as to what was (or more accurately was not) in front of her. Not knowing what to do, she reached one of her hooves into the space. It seemed harmless, but when she pulled her hoof back out, it'd disappeared. Luckily she still had several extras, but it was certainly disconcerting, especially since it was beginning to grow.
Were Twilight Sparkle there, she would've explained to Pinkie what exactly the anomaly was, a small expanding rift in the space-time continuum caused by the excessive abuse of the laws of physics - in this case, the abuse of hammerspace. As a result, anything caught in this rift would be blinked out of existence. However, Twilight was not present. And even if she were, Pinkie Pie wouldn't have had time for an explanation, as the situation was quickly escalating to a very dangerous point.
The rift was quickly expanding to fill the room, blinking anything it touched out of existence. Were nothing done about it, the entire town would soon be engulfed, followed by all of Equestria and the universe it inhabited. But there was nothing to be done. Even if the world's greatest minds were gathered there, none would know what to do about it, and even if they did know what to do, doing so would be impossible for any pony in existence, save one.
Luckily for all of us, that one physics-manipulating pony was in the room with the rift. She didn't understand much about this rift, but she understood what it was doing. No matter what was done, their universe would be sucked into this void, leaving nothing behind. Pinkie thought for a moment, and came to the only logical conclusion: if this universe was doomed, she'd simply create a new one. And so, without another thought, she entered the void.
Ponies of Equestria screamed in terror as their world was destroyed. They tried to run, but inevitably everything was engulfed. Most ponies eventually just gave up and accepted their fate. It was a world in sorrow, broken and on its knees until it was eventually put out of its misery.
Within the void, however, a giant explosion rocked the nothingness. All of a sudden, matter appeared and time began again. Stars and planets were born, and on the planet Earth, life began. Creatures evolved and a dominant species emerged, only to be destroyed to give way to another species that was doomed to eventually die out itself. Dinosaurs, humans, ants, each in turn rose and fell until ponies evolved to such a point that they gained real intelligence.
They were the first species to stay dominant through peace, and so they prospered. Great minds pondered the meaning of the world and great leaders made sure they'd be able to continue without interruption. Eventually two great rulers took control of the land, and confident in their happiness, the ponies settled down and set their focuses on the everyday.
They all eventually found their purpose. Some were meant to fly, others were meant to learn. And in the small town of Ponyville, a pink pony by the name of Pinkamena Diane Pie would find her true purpose through a bag of oatmeal.
And that's how Equestria was made.
