Harry Potter: The Story of Krismile

Lyle's life, in short:

Age two: His parents and sister are brutally killed.

Age six: Adopted by "Good" Mr. Good.

Age eleven: Starts school.

Age twelve: Slacks off every day.

Age thirteen: Learns the truth about his origins, and his CPU fries.

Age fourteen: Becomes hopelessly lovestruck.

Age fifteen: Becomes a Death Eater.

Age sixteen: Spends every day making up for all that slacking off.

Age seventeen: Goes to meet Merlin (dies).

Theme: "At least I did my best."