In case you missed it, Matt Groening has revealed the inspiration for the fictional home of the 'Simpson' family. According to an interview Groening gave to Smithsonian magazine, the fictional Springielf was named for Springfield, Oregon, the town next to where he grew up.
Judging by the hundreds of comments posted on the article, a good number of his fans are disappointed that he revealed the source of name before the end of the show. After all, the secret location of Springfield has been the longest running gag of the show.
Springfield is the common town name in the United States. Every state has one, so every state has had an opportunity claim they were the home of 'The Simpsons' and since nobody knew for sure, nobody could definitively prove otherwise. This made the situation all the more funny because everyone wanted what they essentially could never have.
So, my question is this: When is the right time for a writer to reveal a secret they have kept from their readers? My answer: Never.
By definition a secret is something you do not share. If Orson Welles had revealed to reviewers the meaning of "Rosebud" there would have been little point in anyone watching 'Citizen Kane.' Since 'The Simpsons' is a weekly sit-com it seems unlikely viewers will refuse to watch the show based on his revelation, but their disappointment is palpable. Groening added to this angst by refusing to name the location for the past 23 years only to release it suddenly and unexpectedly in a rather off-handed way.
What if George Lucas had revealed the secret relationship between Luke and Darth Vader in promotional interviews for "The Empire Strikes Back?' Not only would it have possibly hurt ticket sales it also would have ruined what has become arguably the most epochal moment in film history.
I am not trying to second guess Groening's decision to reveal the secret of Springfield. And I am not here to tell you that you should or should not keep secrets from your readers. I am here to remind you that there is something to be said for keeping a secret a secret, and that revealing your secret might have an effect which you could not foresee. So be certain you consider carefully before revealing yours.