Young Sheldon’s series finale on Thursday wasn’t just the perfect send-off for the Cooper family, giving the characters closure after seven seasons, it also included a trove of Easter eggs for loyal, eagle-eyed viewers.
During a recent interview with PEOPLE, executive producer and co-showrunner Steve Holland explained how the Young Sheldon crew went about figuring out what to feature in the two-part finale. Part of the process included visiting a museum on the Warner Bros. lot near the Young Sheldon set.
“The Big Bang Theory set is in a Warner Brothers museum here on the lot, so we went to the set in the museum and we started going through it and saying, ‘Well, what would Sheldon still have?’ ” Holland explains, adding they were “just picking things off the set.”
“So, the Easter eggs are a collection of things from Big Bang Theory and from Young Sheldon from his childhood that are sort of hidden in the background,” he adds. “Hopefully, people aren’t looking for it necessarily the first time around, but if you want to go back, freeze-frame and play a little game of what can you spot, there are a bunch of things.”
In adult Sheldon’s (Jim Parsons) home office, where he’s working on his memoir — to the amusement and chagrin of Amy (Mayim Bialik) — a number of mementos surround him. His childhood train set sits above the office door while comic books are lovingly preserved and stashed to the right of Sheldon’s desk.
“We thought in this world they now have — this house in Pasadena — and maybe Amy was like, ‘You can have that stuff, but it goes in your office. It doesn’t get to go in the rest of the house,’ ” Holland explains.
There are also nods in Sheldon and Amy’s dialogue to their kids, who aren’t following in their parent’s (intellectual) footsteps, and a reference to Penny, the character portrayed by Kaley Cuoco in The Big Bang Theory.
When Amy breaks it to Sheldon during one scene that their daughter, who goes unnamed, wants to take acting classes, he exclaims, “We should have never let Penny babysit!”
“I love that we get to sort of acknowledge Penny, because I think Penny and Sheldon’s relationship was always such a great central part of Big Bang Theory,” Holland continues.
He also pointed out in an interview with Entertainment Weekly there was another Easter egg viewers almost certainly missed. In the final moments of the finale, Sheldon stood on Caltech’s campus, quietly taking in the college’s sign. Then, a faculty member approached him and asked if he was lost. That faculty member was played by David Saltzberg, who served as a science consultant on Big Bang Theory and Young Sheldon.
“We didn’t want it to be distracting,” Holland adds. “We realized [Saltzberg], other than Chuck [Lorre] and Jim [Parsons], has been with this character the longest, because he worked on the first Big Bang Theory pilot, so it’s really just a nice way for us to honor David and all the contributions he’s made to both of these shows for the last 16 years.”
In that sense, the finale serves as a love letter to loyal viewers who enjoyed both The Big Bang Theory and Young Sheldon.
“I feel incredibly proud of these last few episodes, specifically these last three episodes, I think are some of the best we’ve ever done,” Holland tells PEOPLE. “It’s a difficult mixture of emotions, and getting into those last few episodes was literally saying goodbye to someone almost every day. So it was great to watch these episodes come to life.”
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Seasons 1 to 6 of Young Sheldon are available to stream on Netflix. All 12 seasons of The Big Bang Theory are available to stream on Max.