Warning! Spoilers ahead for Young Sheldon season 6, episode 5.
The Big Bang Theory, the Leonard and Penny's love story was baked into the sitcom's narrative from the get-go. Given Sheldon's relationship with his roommate, he was involved in its highs and lows for more than a decade, especially during its earliest years.
Sheldon wasn't exactly welcoming of Penny, despite that, he didn't give the couple a lot of grief when they started doing sleepovers at Apartment 4A even when they were being loud at night. Young Sheldon season 6, episode 5 reveals why the socially-inept genius spends the night at his college dorm to prepare for an early morning class. Unfortunately for Sheldon, the rest of the facility becomes alive at night, making it difficult for him to get a restful sleep. He tries to amend this by becoming the resident advisor, but spectacularly fails. This forces him to eventually come to with the noise, giving him the training to block out any of the potential commotions from Leonard's room whenever Penny would come over.
Why Sheldon Was Tolerant Of Penny
Before meeting the Pasadena gang, Sheldon was having a difficult time socializing. Leonard, Howard, and Raj were somehow obliged to hang out with him because he saved their lives from their experiment gone wrong. Surprisingly, however, Sheldon was tolerant of Penny because of Missy. As seen on Young Sheldon, the Cooper twins have a close relationship — something that The Big Bang Theory wasn't able to fully explore because of Missy's limited appearances on the sitcom. It's clear, however, that Penny and Missy have a lot of similarities; they may not be academically gifted, but both have street smarts, kind and spunky. Since Penny reminded Sheldon of his own sister, he was more tolerant of her, until they developed their special friendship.
Why Sheldon Never Talked About College As Much On Big Bang Theory
For someone who likes to bring up his academic achievements, Sheldon interestingly didn't talk much about his undergraduate adventures compared to his master's and doctorate experiences. Young Sheldon shed light on Sheldon's academic history when it was revealed that instead of attending Ivy League institutions like CalTech, Harvard, or Princeton, Sheldon went to East Texas Tech. The decision stemmed from Mary's inability to let go of her youngest child while he was still a kid. So, as a compromise, the family decided that Sheldon would go to a nearby college, so he could still come home every day. East Texas Tech is by no means a bad school. There, Sheldon is able to spend time with his two mentors, Dr. Sturgis and Dr. Linkletter, which is a big bonus. However, it doesn't have the same prestige as Ivy League schools, so he isn't inclined to talk about his time there.
In any case, East Texas Tech looks to have helped Sheldon out in one aspect of his life, by helping Sheldon tolerate his friends' romance, which he was right to do. After all, it's clear that only Penny can make Leonard truly happy because like him, she, too, developed an odd but genuine friendship with the socially-inept genius. Leonard dated a lot of other girls on The Big Bang Theory, but no one was able to get along with Sheldon as well as Penny did. Several of the Pasadena gang have already made their Young Sheldon voice cameos, it's high time CBS brings the Hofstadter in by letting Penny and Leonard adult Sheldon in his next voice-over session.
Young Sheldon season 6 airs Thursdays on CBS.