Imagine learning that Darth Vader was really Luke Skywalker's father before you had the chance to see The Empire Strikes Back.
Prematurely revealing the ending, or a major plot twist, of a film, television show, or book is perhaps the biggest crime in pop culture etiquette. Before the birth of social media and the omnipresence of the internet, staying away from spoilers was relatively easy. But in today's social media age, with continuous, free-flowing and free-roaming information, staying away from unwanted information has become extremely difficult.
While there are people who spoil endings on the internet for fun (known as "trolls") most spoilers on social media are the result of an honest mistake: people eager to discuss a film or book they have just finished.
Spoiler etiquette - meaning where and, more importantly, when to discuss sensitive information - has been well established among diehard fans, but is still a grey area for most others.
Even professionals get it wrong.
Respected film trade publication The Hollywood Reporter angered a legion of fanboys last month by publishing a story on the death of Peter Parker (aka Spider-Man) in the 700th issue of The Amazing Spider-Man comic book at 9.57am on the day of the book's publication.