Tuesday Talkback - Worst retcon?

I saw the pilot for The Carrie Diaries a while back and was somewhat surprised to discover that I found it rather cute and charming.  Given that I can't take more than 30 seconds of Sex & The City without wanting to vomit at the terrible acting and the worse puns.  (Full disclosure: thanks to my wife being a fan, I've seen about six full episodes... and one of those I've ended up seeing at least three times.  If your curious, it's the one with SJP and her current boyfriend having their cabin weekend ruined by Detective Logan from Law & Order.)

Anyway, I read a few reviews of the show today and one of them led me to this article complaining that Carrie's backstory in The Carrie Diaries is incompatible with what audiences learned of her history on Sex & the City.  And now an entire generation of Manolo Blahnik-wearing fans get to learn a term familiar to anyone who's read comics for any decent length of time: retcon.

"Retcon" is short for "retroactive continuity."  Basically, it refers to when some element of backstory is reestablished after the fact.  Over the years, it's mostly been used to call out examples when the new elements clash with older elements (as in the above example), but it can also refer to instances where the new detail fits in perfectly and brings new depth to the story.  Darth Vader being revealed as Luke's father is an example of this.  When Vader was introduced, it wasn't set in stone that he was going to turn out to be Anakin Skywalker, so the decision to go in that direction in Empire Strikes Back is a clear retcon.

This sort of thing happens a lot in comics, where new creators love to come in and say "Everything you know is a lie!"  Sometimes they work, but often they just make stories more confusing.  I don't know WHY comic creators like meddling with characters origins.  All I know is that whoever gave Jeph Loeb (in 2000's "Return to Krypton") and later Mark Waid (in "Superman: Birthright") permission to muck around with what had been a consistent Superman origin since 1986 deserves a kick in the balls.  That really ruined several years of stories as later writers tried to make sense of the mess they left.

I'm sure everyone reading this has seen some kind of retcon, so what are your least favorite examples?  TV is full of minor examples like the Cunninghams having an older son who only existed for a few episodes on Happy Days, or Jerry Seinfeld referring to his sister on Seinfeld before later episodes reaffirmed he was an only child.

But the big ones can really put you off of a show.  The example that leaps immediately to mind for me is from the TV show Brothers & Sisters.  I had checked out the show early in its run due to the involvement of Greg Berlanti, who among many other great shows, created Everwood, one of my all-time favorite series.  The first few eps didn't grab me, but I was motivated to return about 2/3 of the way through the first season when they added Everwood's Emily VanCamp to the cast.

VanCamp was introduced as Rebecca, who soon discovered she was the illegitimate daughter of the Walker family's deceased patriarch.  This led to a lot of conflict with the Walker siblings, but Rebecca soon was welcomed into the family... for about a season.  Towards the end of the second season, the writers reversed course and revealed that - SURPRISE - Rebecca was never a Walker at all.  So a full year's worth of stories about the family coming to terms with her presence and Rebecca dealing with gaining such a large family suddenly seemed to be rendered null and void.

(Supposedly this change was made so they could capitalize on the chemistry between VanCamp and David Annable, whose relationship on the show was that of siblings until the Rebecca retcon removed any hint of incest.)

At that point, I felt like they'd pushed an unneccesary reset button on Rebecca, and as she was the character who had gotten me into the show, I found myself with little incentive to stick around much past the start of the following season.  It's a shame because the show was generally well-acted and the writing was usually pretty solid, but that twist broke a lot of my investment in the characters.

Actually, that was the real shame.  I wanted to keep enjoying the show and there was a lot there that still was working (evidenced by the fact it ran a further three seasons).  The Rebecca aspect was just one aspect of a very large show, after all.  Thing is, there's a risk that comes with taking chances and sometimes your audience isn't going to be able to follow you after certain choices.  A viewer less invested in Rebecca's story might have rolled with the punches better.  For me, it had been one of my favorite aspects of the series, so the change-up was a bitter pill to swallow.

So do you have any similar examples?  What retcons have earned your ire?