After the whole "casting mind control magic on her friends" incident, Starlight spends a sleepless night staring out her bedroom window and wondering how she can ever manage to apologize to them. And to the rest of Equestria for everything else she's managed to foul up over the years, too, now that she thinks about it...
My entry in the October 2016 Writeoff, "The Darkest Hour," this story came in 10th place.