According to an oral history of "The Big Bang Theory," Jim Parsons' co-stars were absolutely floored when the star revealed that he wouldn't continue on with "The Big Bang Theory" — and the show would be ending as a result of his exit.

In "The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series" by Jessica Radloff, Johnny Galecki — who plays Leonard Hofstadter, the on-screen best friend to Parsons' Sheldon Cooper — said he stood by and watched as his co-stars "emotionally crumbled.

" Even though Parsons hoped the show would keep going without him, showrunner Steve Molaro said that was never an option: "There was never a question about continuing on without him. The show was this ensemble and the thought of doing some strange version without him didn't seem right."

This caused plenty of strife in the immediate aftermath of the announcement, though, when Parsons told his colleagues he wouldn't return and creator Chuck Lorre joined him to say the show would also ending. "But there was a lot of crying in the room. Kaley [Cuoco], in particular," Lorre said. "It was a blow. And there was no way to soften it by giving them a heads-up.

I didn't know any other way to do it."

"The shock of, 'Oh my God, what is next?' was scary," Cuoco, who played Penny on the series, recalled. "I mean, we cried for hours that day. We thought we were going to do another year, so all of the sudden your life kind of flashes before your eyes. I looked at Chuck and said, 'What are we going to do?' I couldn't breathe. It just felt like a death, but also a new horizon for everybody as well."

Johnny Galecki thinks the announcement wasn't handled well

For his part, Johnny Galecki said he was really surprised by this reveal — and that he thought that surprising the entire cast with this major bombshell wasn't the right move. "I was shocked," he recalled. "We were just blindsided that day. And not necessarily shocked by Jim's decision, but that he hadn't had that conversation with his castmates first to prepare us. So yes, it could have been handled better. We're a family; have a conversation. And I don't even disagree with how Jim felt, because in many ways, I felt the same way. I just disagreed with how it was managed."

Understandably, it was difficult for Galecki to watch his co-workers completely break down learning that their show was ending a lot earlier than they expected.

He specifically mentioned that Kaley Cuoco — who dated from 2008 to 2010 and were also on-screen love interests — took it so hard that it was difficult for him to bear, saying, "[it was] tearing me to shreds watching Kaley break down and see the tears from everyone."

Jim Parsons probably won't come back as Sheldon Cooper

Even though he serves as an executive producer for the Sheldon Cooper-focused spin-off "Young Sheldon," where the character is played by Iain Armitage — and — Jim Parsons told Justin Long on the actor's

that he wouldn't show up to in the future. "At this point, hell no," Parsons told Long. "In 30 years, maybe. You'll have to ask me then. It'll depend on how nice the beach is I'm living on. If it's flooded away, I might come back."

That said, he also told that he didn't waste a minute getting away from the show after it was over. Asked how long it took for him to return to life in New York after living in Los Angeles for the series, Parsons said, "We did our final performance on a Tuesday night. On Wednesday, we did the handprints and stuff at Grauman's Chinese Theatre. Thursday morning, I was on a plane out of L.

A." This isn't to say, in any way, that Parsons had some sort of miserable experience on "The Big Bang Theory," but he also was definitely ready to move on.

In the end, Jim Parsons left The Big Bang Theory behind for an emotional reason

On a different podcast, Jim Parsons told David Tennant that a real-life tragedy also led to his exit from the series — one of the dogs he shared with now-husband Todd Spiewak was having serious health problems. On "" Parsons told the "Doctor Who" star, "I was exhausted.

I was really upset about, more than anything, one of our dogs was getting really at the end of his life around then."

To make things that much worse, after losing his pet, Parsons broke his foot: "It was the scariest moment for the next couple of days because I felt like I was at the edge of a cliff. I was teetering and I saw something really dark below between the death of the dog."

"The bottom line was that it was a really intense summer," Parsons concluded to Tennant. "The dog passing away, he was 14, and Todd and I had been together for 15 years at that point, so it just was the end of an era.

I had this moment of clarity that I think you're very fortunate to get in a lot of ways, of going 'Don't keep speeding by'. You know? 'Use this time to take a look around.' And I did."

Jim Parsons wanted the show to go on without him

That wasn't the end of Jim Parsons' revelations on David Tennant's podcast, though. The actor continued by saying that at the time, he simply wanted to spread his wings, and he was thinking to himself, "I think there's other things I need to try and do.

I don't even know what they are, but I can tell that I need to try."

Again, though, Parsons said he really hoped the rest of the cast and crew would just carry on without him. "I never had feelings of not wanting the show to go on without me," Parsons admitted. "In fact, I kind of felt the opposite about it. I had a feeling of 'there's so much good going on here, so many people love it.'"

In the end, the show did not go on without Sheldon and Parsons, and the series called it quits after a whopping twelve seasons. Parsons, Johnny Galecki, Kaley Cuoco, and the rest of the cast certainly left a lasting impression, as the show's popularity seems like it might never fade, especially with the show streaming exclusively on Max. It's understandable, though, that Parsons wanted to do something different after all those years playing Sheldon Cooper.