"Zecora was tellin' me that in other lands, ponies drink somethin' called 'alcohol'. They've got uses for cider and grape juice we can't even dream of!"
"We have parties all the time in Equestria. I wonder why there's never any alcohol?"
"I will tell you the story, young ones. Once upon a time, there were two regal sisters who ruled Equestria together. But as time went on, the elder sister became resentful. The ponies drank and partied through the night her younger sister brought forth, but slept hungover through her beautiful day. In bitterness, the elder sister banned alcohol throughout the realm, and instituted a 9:30 curfew so ponies wouldn't stay out too late. And when the younger sister ventured a calm and well-reasoned word in protest, the elder sister banished her to the moon for a thousand years because she's a big dumb meanie jerkface. The end."
"Wow! Thanks, Princess Luna! Now I know!"
"Oh, dearest sister. Are you filling the ponies' heads with more of your ridiculous tales?"
"Information wants to be free, Celestia! History will vindicate me! You can't hide forever from your decisions!"
Oh god, revisionist fanfic. I've become what I most despised.