Young Sheldon finale cameo changes the meaning of the entire series

Two stars of ‘The Big Bang Theory’ featured in the prequel finale

A cameo in the finale of the Big Bang Theory spin-off Young Sheldon may have just changed the way fans interpret the entire series.

Jim Parsons, who played the lead character Sheldon Cooper in the hit sitcom, made an appearance in Thursday’s (16 May) series finale of Young Sheldon, alongside Big Bang Theory co-star Mayim Bialik.

Young Sheldon follows a younger version of Parsons’ character, played in the series by child star Iain Armitage.

Parsons serves as the narrator of the series, without featuring onscreen. However, in the series finale, it is revealed that the events of Young Sheldon are in fact the contents of a memoir, penned by Sheldon.

Viewers were quick to note that the revelation retroactively colours much of what the series has previously shown – and potentially provides an explanation for several Big Bang Theory-related plot holes that fans had spotted.

“Having the entirety of @YoungSheldon be from Sheldon’s memoirs is a clever way to establish his ‘unreliable narrator’, which is enough to explain away the contradictions from @bigbangtheory episodes,” one fan wrote.

Another commented: “Also the fact that Sheldon is telling his story now that he has kids, it makes sense why #YoungSheldon differs from his stories in #TBBT. He sees everything in a new context. Maybe he still doesn’t agree with all their choices but he understands them.”

Jim Parsons in the ‘Young Sheldon’ finale (Bill Inoshita/Warner Bros)

In the second half of the final episode, audiences catch up with Sheldon as an adult, along with his wife Amy (Bialik). It is revealed that the couple now have two children, who have seemingly drifted away from their parents’ STEM background, pursuing interests in hockey and acting instead.

Speaking to People, co-showrunner Steve Holland described the efforts to get Parsons and Bialik to reprise their famous roles. “I think they were both excited,” he said. “Jim's obviously been a part of the show. He's an executive producer. He's been the narrator. I think Mayim literally said, ‘Anything you want me to do, I'll come there and do.’”

“They’re both so talented,” he added. “I think they would say that there was some nerves about stepping back into these characters and that they weren’t quite sure they would find their rhythm. From watching them do it, it felt so effortless.”

“Just watching them work, sitting, editing and watching the takes, they make so many smart and interesting choices on each line,” he said. “It was just really a joy to watch.”

Young Sheldon aired for seven seasons from 2017 to 2024.