Warning! Spoilers ahead for Young Sheldon season 5.
CBS' Young Sheldon explains how Sheldon and his friends' most fun tradition on The Big Bang Theory started. The success of the premier sitcom has allowed and required the network to continue capitalizing on the popularity of the original series. So while it tells his own narrative, Young Sheldon also often references The Big Bang Theory, and has used it as an opportunity to explain some of older Sheldon's behaviors and relationships in the original show.
The Big Bang Theory was still a ratings juggernaut for CBS when its cancellation was announced ahead of season 12. Luckily, at that point, the network had already launched Young Sheldon, Big Bang Theory's first and only spin-off thus far. For its first two years, it aired back-to-back with the original show, but ever since The Big Bang Theory ended in 2019, Young Sheldon has stood on its own. Despite this, it has consistently incorporated its parent show thanks to regular references and even guest appearances from both Mayim Bialik and Simon Helberg as Amy and Howard, respectively. Oftentimes, however, Young Sheldon's ties to The Big Bang Theory are executed more subtly, like this latest one.
In Young Sheldon season 5, episode 13, "A Lot of Band-Aids and the Cooper Surrender," Sheldon meets his dorm neighbors at East Texas Tech. After realizing that they share the same interests, including playing Dungeons and Dragons, he starts hanging out with them. At one point, they started gathering to play video games and it's when Sheldon is introduced to Chinese food. Unfortunately, the socially-inept genius overeats and ends up with a bad case of gastritis. Nonetheless, the experience stuck with him so he recreated it with his friends on The Big Bang Theory and it became one of the show's best traditions. Cleverly, then, Young Sheldon explains why he and the guys used to spend Friday nights playing (retro) video games and having Chinese food in TBBT.
Before life got in the way and they were still all carefree bachelors in The Big Bang Theory, adult Sheldon and the guys used to have their whole week planned out beyond just Fridays. For a time, they went to The Cheesecake Factory for Tuesday dinners, with Sheldon always ordering barbecue bacon cheeseburger. Wednesdays was both Halo night and comic book night. Finally, Saturday was laundry night. However, as The Big Bang Theory went on and Howard and the rest of the boys started dating, following this nightly schedule became trickier until they ultimately dropped it. When Sheldon moved out of Apartment 4A and lived with Amy, adhering to their old schedule became rarer. Instead, they all just gathered together to eat and hang out.
It's uncertain if Sheldon's geeky East Texas Tech dorm friends will show up again in Young Sheldon. The semester is still ongoing which makes it possible, but Mary (Zoe Perry) finding out about his gastritis, might cause her to forbid her son to spend time with them again, not knowing that it was Sheldon's fault. This could very well explain why he never mentioned their existence in The Big Bang Theory.
Young Sheldon season 5 airs Thursdays on CBS.