Young Sheldon's season 4 premiere highlights the biggest plot hole in The Big Bang Theory's finale. In 2019, the Pasadena-set sitcom wrapped up its 12-year run on CBS. And despite an uneven final season, it delivered an emotional and mostly-satisfying two-part finale that saw Sheldon and Amy win the Nobel Prize in Physics for the work on Super Asymmetry.

Much of The Big Bang Theory season 12 was focused on the newly-married couple's scientific research. Coming off of their wedding, Sheldon and Amy worked tirelessly on their project, with the show giving them various high and low points through their journey to make for a better-earned ending. Sheldon was always enamored by the idea of being a Nobel winner — something that he knew he wanted to be even when he was still in high school back in Galveston, Texas as seen in Young Sheldon. That ultimate dream finally came to fruition thanks to his collaboration with his wife and the support of Sheldon's friends who all flew to Stockholm, Sweden for the award ceremony.

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The Big Bang Theory's final moments featured Sheldon's best and most earnest scene in the series. After several commotions that almost had his friends packing and going back home before he even got the coveted award because of his insensitivity, the socially-inept genius made up for it by personally thanking each and every one of his pals during his acceptance speech. In this rare instance, Sheldon gave his gang credit for sticking with him all these years despite his unreasonable quirks. While this was such a touching moment, there was one glaring problem with the whole Nobel Prize award ceremony — the absence of his family; this is something that Young Sheldon's season 4 premiere, "Graduation," makes painfully clear.

The Big Bang Theory finale of the cast supporting Sheldon and Amy

In the CBS prequel spin-off episode, Sheldon graduated high school as the valedictorian, hence him needing to deliver a speech. Instead of his usual confident self, however, he stood in front of Medford High School admitting that he's scared of the impending change in his life, but he's more than ready to tackle it thanks to some words of wisdom from Missy the night before the ceremony. He publicly thanked his twin sister for her encouragement, which is a rare case considering how he hates giving credit. This made for a poignant moment in Young Sheldon, showcasing just how important Missy and his whole family is in his life journey. Given this, it's such an odd thing that The Big Bang Theory finale didn't have them during Sheldon's proudest moment. The original show didn't even give any justified reason why his relatives couldn't attend the Nobel Prize ceremony.

Granted that The Big Bang Theory was more focused on Sheldon's relationship with his friends who chose to still be with him despite his bad tendencies instead of his blood-relatives who had no choice but to deal with him, it's worth noting that the sitcom featured all of his family members throughout its 12-year run. In fact, they even found a way to show George Cooper Sr. in the final year who has long been dead. Meanwhile both Georgie and Missy, as well as, Mary were at Sheldon and Amy's wedding in the season 11 finale. The show didn't have to feature all of Sheldon's remaining family members in the finale, but they could've at least brought in Mary to see her son reach his life-long dream. Doing this would've also highlighted the importance of the events of Young Sheldon's in the titular character's overall story instead of an optional offering.

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