Warning! Spoilers ahead for Young Sheldon season 5 finale.
The Young Sheldon season 5 finale explains one of Sheldon's worst traits in The Big Bang Theory. CBS staged a tamer year-ender compared to its predecessor with the comedy's focus shifting back to its titular character. It did feature a direct reference to The Big Bang Theory, however, as the young Sheldon (Iain Armitage) dons his first Flash shirt. Aside from that, however, the Young Sheldon season 5 finale may have revealed the origins of a bad Sheldon trait as seen in the geek-centric sitcom.
CBS' storytelling for Young Sheldon took a darker tone in season 5. As the Cooper kids grow old, they are also faced with more mature issues. Despite being sidelined for some parts of the year, Sheldon had some interesting arcs throughout the season. That included the return of Paige (McKenna Grace), who was struggling with college and life in general after her parents split up. In the Young Sheldon season 5 finale, Sheldon develops an intense fear of the future after seeing what his parents Mary (Zoe Perry) and George (Lance Barber), as well as, Georgie (Montana Jordan) are going through. Amidst all this, however, Sheldon may have also picked up an appalling trait from his father who refuses to work at the grocery despite being in a financial bind.
After both George and Mary lose their jobs in Young Sheldon, the Cooper patriarch starts to get worried about their financial situation. Realizing how big of a problem this is, Mary scours the town for any new job opportunities. She eventually finds both of them work at the local grocery, but George refuses to take it because he deems it below him following his coaching stint at Medford High School. This particular viewpoint with regard to the supermarket job may be something that Sheldon inherited from his dad. In The Big Bang Theory, he looked down on blue-collar workers. While Sheldon already thought highly of himself, he didn't have any problem imposing that on people doing those types of jobs. He even said that Penny's (Kaley Cuoco) job at The Cheesecake Factory as a bartender didn't need any brain work. It's worth noting that he also saw engineers the same way — until it was revealed in Young Sheldon season 5 the real reason he hates engineering.
While George already refused to work at the local Medford supermarket, he may not have any choice but take the gig if he continues to struggle to find his next employment. After he shoots down his wife's offer, Mary goes around town again to find herself a different job. She ultimately scores work at the local bowling alley but that means that she has to work with Brenda Sparks (Melissa Peterman) every day. That puts him in a tricky spot considering his secret attraction to his divorced neighbor — something that will continue to be a part of the show’s storytelling moving forward. Between this and Georgie and Meemaw's arrest in the Young Sheldon season 5 finale, the Cooper patriarch is at a tough spot, and if he can't find another job elsewhere, he will have to ultimately take that grocery gig. This doesn't mean, however, that he'll stop looking down on it. Perhaps, it might even further fuel his prejudice against supermarket workers that he starts to be more vocal about it at home where Sheldon can hear him. This stays with the boy genius, hence his perspective on blue-collar job workers in The Big Bang Theory.
The Coopers' financial woes may actually be what transforms George into a bad dad in Young Sheldon. After five seasons, the character's depiction remains to be the spin-off's biggest plot hole with The Big Bang Theory. Using the family's money problems to explain the sudden change in him works in terms of what's known about the character thus far considering that he has always been worried about their cash flow.
Young Sheldon will return for season 6 on CBS.