Twilight accidentally steps on a snail. This makes her sad. As the years go on, several other things happen.
A new student arrives at Ponyville Elementary
Rarity and Rainbow Dash: A romantic pairing so odd that even they don't get it.
A prequel to "Nightmare Night and Nyx."
A really really really short vignette, that grew.
The mane 6 are sent out to find more alicorns.
Even when you know somepony well, they can still take you by surprise. Fluttershy learns something about Twilight Sparkle that she had been keeping carefully hidden.
Twilight becomes an alicorn princess-- much to Nyx's surprise.
Nyx's first Nightmare Night
Everyone's Favorite Fillies Find a Fun way to expand their vocabulary.
Innocent ponies get stoned without realizing it.
The Cutie Mark Crusaders have a sleepover.