When you've got yourself a bona fide TV hit, like CBS does with "Young Sheldon," you don't typically end the show at the height of its popularity. But then, there's nothing typical about the Cooper family, or their brilliant, sometimes misunderstood son, Sheldon. Also atypical for a show that's brought a lot of laughs over the years, there sure were a lot of tears backstage last week, when executive producers Steve Molaro and Steve Holland were editing the final frames of a show whose success has surprised even them.

Molaro said he was crying his eyes out: "Literally crying, yes," he said.

Neither producer expected their show to become a huge hit. "Never, no," said Molaro. "We would never dare to assume we know what we're doing at that level."

While "The Big Bang Theory" was nearing its end after 12 seasons (winning 10 Emmys along the way), in 2017 the character of Sheldon Cooper was re-envisioned as a child prodigy in a prequel series, "Young Sheldon." Holland said, "To do what Jim Parsons does on 'Big Bang Theory' is a one-in-a-million shot, because there's so many ways that character could come off grating or irritating, but there's such a sweetness to Jim that, like, it sort of breaks through that. And you're like, 'Well, is it possible that there's a kid who's eight who can do that?'"

Enter Iain Armitage, whom they found from his audition tape, recorded on a cell phone over Christmas break at his grandparents' house.

"Sunday Morning" first met Armitage when Tracy Smith interviewed him back in 2017. She asked him, "What do you think you're going to be in 20, 30 years?"

"Hopefully I'm doing magic tricks in Las Vegas," he replied.

In fact, Armitage has pulled off a sort of magic trick, helping carry a network TV hit, and becoming famous, all while staying – surprisingly, disarmingly even – pleasant to be around.

Now 15, Armitage said, "I have to really constantly remind myself that if I'm ever sad about this ending, I can only be sad because it's been so incredible and so wonderful."

The set for "Young Sheldon" might feel like home ("It is funny, I think of this as my house," he laughed), but Armitage said he's never quite gotten used to being a TV star. "When I go home, and when I see, 'Thursday night at eight, "Young Sheldon",' and I see commercials for it, it feels really weird! But I think aside from just delivering the lines, I think it's trying to stay true to Jim Parsons, and his incredible Sheldon, while kind of making it my own to a degree."

Parsons says there's a certain irony to the fact that many Sheldon fans are unaware there ever was a show called "The Big Bang Theory." "Almost all of my friends who have children always tell me, '"Young Sheldon"'s on all the time in our house,'" said Parsons. "And so, it's playing to a demographic that wasn't born when we started our show, a demographic that frequently doesn't know what you're talking about when you say 'Big Bang Theory,' but they watch 'Young Sheldon.' And that's been great."

Which brings us back to where we started: Why are the show's creators ending things considering how popular it is? For one, the timeline. After seven seasons, "Young Sheldon" is starting to collide with plot points from "The Big Bang Theory," which gets complicated.

But also maybe, because as Molaro sees it, the character of Sheldon Cooper has accomplished his mission, which it turns out is a pretty important one: "Some of my favorite moments are when a mom will come up with her son after a panel and say, 'My son's a lot like Sheldon,' and I know what she means. 'He's having a tough time. He's different. And thank you for making kids like him more accepted.'

"And the fact that we could even move, maybe, the needle a little bit on that in the world is a reason to do this whole show," he said.

To watch a sneak peek of the series finale of "Young Sheldon" click on the video player below:

For more info:

• "Young Sheldon" on CBS and Paramount+

     
Story produced by John Goodwin. Editor: Mike Levine.

      
See also:

• For 6-year-old critic Iain Armitage, theater reviews are child's play

In:
• The Big Bang Theory
• Young Sheldon