It Was His Sled: Werther's suicide. The book is several centuries old at this point, so...
Memetic Mutation: The book actually started a fashion for blue coats and yellow breeches. And suicide, of course.
Misaimed Fandom: So many people have looked to Werther as inspiration for their own suicides that this book is frequently used as a case study of copycat suicides.
Signature Scene: As the page quote shows, what people tend to remember is the striking scene where Werther first meets Lotte as she is in the process of cutting bread and butter for her eight younger siblings. (In real life, Goethe experienced this scene with Charlotte Buff the day after the ball).