Back when Pinkie Pie was still a filly, Maud joined her first party. After much retrospection, Maud came to a better understanding of both her and her sister.
The love stolen from the Canterlot invasion was finally enough to awaken sapience in Chrysalis' changelings. But to her horror, it became apparent that these were no longer truly her changelings, or even changelings at all.
What if you couldn't trust your own memories? What if the passage of time itself was suspect? And who's going to be that one pony that you can't quite remember?
Pinkie Pie found a book with enchantments reserved for noble foals, so, naturally she wanted to add one to herself. Now she is able to remember with as much detail as Twilight, but at what cost?