The Big Bang Theory enjoyed an impressive run of 12 seasons between 2007 and 2019. And no cast member received more acclaim than Jim Parsons, who, while on the show, was a four-time winner of the Emmy Award for Outstanding Lead Actor in a Comedy Series.

But it seems that the popular sitcom was actually projected to continue for an additional two seasons beyond the 12th and final season that aired last year.

Production designer John Shaffner revealed this news in a new interview with Metro UK, where he recalled the story of why The Big Bang Theory concluded when it did.

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Jim Parsons ended The Big Bang Theory with 2019 exit

In the Metro UK interview, Shaffner revealed that it was the exit of Jim Parsons that motivated the early finale — and his mid-season decision to quit came as a shock to the rest of the cast.

"We were on a hiatus week and we came back and did our production meeting where we went through the script very quickly," he said. "And then we got up and left and they started doing the table read and somewhere during that time, word had got out that [season 12] was the last year."

"The news that it was ending had been leaked because Warner Brothers had prepared a proper roll-out of explaining it to everybody, but the cast didn't know," he explained.

"What had occurred was Jim Parsons had been in touch with Chuck Lorre over the hiatus week and had said he couldn't come back and do anymore. And Chuck had always said if one member of the cast left the show then the show would have to end."

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The Big Bang Theory had plans for seasons 13 & 14

The news hit especially hard, seeing as there was an expectation that two more seasons were in the cards.

"Warner Brothers and CBS wanted to sign for about two more years," Shaffner continued. "I was back in the office and I found out about this and I went down to stage and I saw Johnny [Galecki] and Kaley [Cuoco] in the comic book store and they were just hugging each other and crying."

"It was very hard for a while for people to accept the decision and the crew was very disappointed because it was a good job."

Today, Shaffner doesn't hold it against Parsons, though. "I really respected what Jim did," he said. "It's better to leave on top. I really appreciate where he was coming from in his head. I knew it was hard. He had a lot of the hardest lines to say."

While The Big Bang Theory concluded in 2019, Parsons does continue to narrate and executive produce the spin-off series for his character, "Sheldon Cooper," in Young Sheldon on CBS.