It was Jim Parsons decision to walk away from CBS’ The Big Bang Theory after 12 seasons, which meant that the show itself would end after 12 seasons, since it would be weird for The Big Bang Theory to go on without Sheldon Cooper.
“It was the first time in my life of doing this show that it occurred to me that I might want to not do another contract after 12 was up,” Parsons told a reporter. “I don’t know if it’s because I’m an Aries or just because maybe I’m in touch with myself. Whatever it is, once I had that thought, I was like, well, that’s your answer.”
Co-creator Chuck Lorre said he couldn’t imagine keeping the show going without Parsons and Sheldon.
“I couldn’t wrap my head around the idea of going on without the whole ensemble,” he told THR. “In pulling it apart and re-approaching it as a fraction of what it was just never felt right to me. I’ve seen other shows try and fail to take a character out of their realm and carry on.”