Being a prequel spin-off to “The Big Bang Theory” and a period piece that starts its story in the 1980s, the CBS sitcom “Young Sheldon” wears multiple hats. This, of course, poses its challenges for Iain Armitage, who plays the titular younger version of the “Big Bang Theory” character Sheldon Cooper on the show. As the young actor found out, filming a show that takes place decades before he was born could also throw minor curveballs that were far more unexpected.

In a 2018 interview with CTV Your Morning, Lance Barber and Zoe Perry — who play George Cooper, Sr. and Mary Cooper, respectively — revealed that Armitage faced a surprising hurdle while filming the show: 1980s technology. “Iain didn’t understand what a dial was,” Perry said about her young co-star’s first experiences with a dial phone. “He was dialing first and then picking up the phone before he was taught on how to use a wall phone,” Barber continued.

Of course, Armitage’s initial instinct was the exact wrong way to handle the prop. The way rotary dial phones work(ed) is that you first pick up the phone, wait for a continuous dial tone signal, and only then dial the number. It’s perfectly understandable that Armitage, who was born in 2008, wasn’t inherently familiar with this outdated piece of tech while filming the show — but for “Young Sheldon” viewers who were actually around during the era the series is set in, the knowledge that a star of a 1980s-themed show found a key piece of the era’s technology so inexplicable may be a grim reminder of the inevitable passage of time.

Apart from occasionally having to wrestle with 1980s communication technology, Iain Armitage had to deal with a starring role on a show that adapted a whole bunch of dramatic moments in Sheldon’s history that had already been established by “The Big Bang Theory.” That meant he had to convey difficult things like Sheldon’s reaction to George Sr.’s death and generally be a centerpiece in a prequel that made creative decisions that worried “Young Sheldon” co-creator Chuck Lorre. Compared to all that responsibility, a piece of obscure technology must have felt like a fairly minor hindrance.

Fortunately, Armitage had the requisite talent to clear all the hurdles, as well as ample backup from a fellow actor who knows the character better than anyone — after all, Jim Parsons personally helped Armitage become young Sheldon Cooper. That’s not to say that the actor didn’t already know Sheldon through and through, though. In fact, in 2022, Armitage noted in an interview with Northern Virginia that Sheldon was already an important presence in his life even before he was cast to play the character:

 “I’ve always identified with Sheldon. I think he’s kind of the universal nerd in such a fun and cool way that people can connect to.”

“Young Sheldon” is currently streaming on HBO Max.