Discord, the spirit of Disharmony, can be… well, eccentric. He loves to see chaos, so when his friends, and more importantly, their elements of harmony, go missing, he takes to the town and has a day out. Of course, then he'll have to clean up before his friends, mostly Fluttershy, get home, or else he'll get the Stare again.

P.S. I know that the Mane Six don't have the elements anymore, let's just say that Discord forgot about that.