When The Big Bang Theory announced that Season 12 would be the final chapter, fans were stunned — and so were most of the cast members. After more than a decade at the top of network television, the decision to end CBS’s longest-running sitcom seemed sudden and unexpected. So what really happened? From major cast decisions and behind-the-scenes developments to the emotional impact on the crew and fans, The Big Bang Theory Finale was one for ages. Despite record-breaking success and millions of devoted viewers, even a juggernaut like The Big Bang Theory had to say goodbye.