S: In the days before a certain sound-light phenomenon, Celestia's personal student is a colt called Sunburst.

L: Over the centuries, many young unicorns have had the unquestionable honor of being the personal student of Princess Celestia. Of course, they were all ultimately surpassed by Princess Twilight Sparkle, but figures of ancient history can hardly be blamed for being succeeded by their descendants.

Except that not all of Celestia's students are ancient history. One of them still lives, and in fact can still remember the day when he was surpassed. He remembers how, for all of his achievements, he was left in the dust by a mere foal.

And to this day, he carries that memory with him.