Lurking throughout seven seasons of "Young Sheldon" was a great tragedy: the family patriarch, George Sr. (Lance Barber) was condemned by "Big Bang Theory" canon to die before Sheldon went to college. Although the show took some liberties with other elements of Old Sheldon's backstory — for example, George Sr., played by Lance Barber, is a much better father in the prequel spin-off than Sheldon ever made him sound — the writers always knew there was no retreat since George Sr.'s death. That event was simply too much of a part of Sheldon's character to rewrite.

For many of the older members of the "Young Sheldon" cast, this inevitable tragedy was known from the beginning. But Reagan Revord, who played Sheldon's cool twin sister Missy, didn't find out about it until after the show had already started. As she explained in a recent interview:

“When I (first) did the show, I was, I mean, nine years old. The Big Bang isn't for a nine-year-old, so I've never seen it before... I want to say it was in Season 1 because I feel like that's something my parents told me just because they saw how instantly close we all were. And so we kind of went through the show knowing that we were going to get there at some point, but it kind of helped because it was like appreciating the scenes with George... Having that knowledge really helped hold those moments.

It was probably for the best that Revord's parents told her the truth about George Sr.'s fate back in season one, as it gave her enough time to come to terms with it before season seven. For the rest of the cast, who all seem to have known about it from day one, that sense of inevitability definitely seemed to help soften the blow a bit.

"(Lance Barber) has known since the beginning of the show that George Sr. has an expiration date," showrunner Steve Holland. explain in a recent interview. "We slowed down the time a little bit. For example, we extended it because the kids, our real cast members Regan and Iain, are 16 in real life. "We spent a year over several seasons trying to keep Lance alive as long as we could, but he always knew this was coming." It's a similar approach to That '70s Show, which started in 1976 and stretched those four years to eight seasons to avoid the blow of the dreaded '80s. But just as 1980 could not be stopped, George's untimely death slowly marched on the cast of Young Sheldon.

Barber confirmed that he knew about it in a press tour interview this year. "I had the luxury of being emotionally prepared for this from day one," he said, though even knowing what was coming didn't stop the production of his final episode from feeling solemn for everyone involved. Like Sheldon's young actor Ian Armitage explain"Everyone was crying. It was so hard. We love Lance so much."