Young Sheldon introduced its titular character as an apt liar if he wanted to, even if The Big Bang Theory season 1 had established Sheldon’s unease with lying before the prequel spinoff tackled the story. While both sitcoms showed Sheldon navigating life with a distaste for dishonesty, he still tried to lie multiple times, in The Big Bang Theory more often than in Young Sheldon. However, if discovering how to lie properly in Young Sheldon opened a new door for Sheldon, The Big Bang Theory showed that he had forgotten all the skills needed to lie, ending up unsuccessful most of the time with the convoluted lies he made up.

Sheldon tried to lie in Big Bang Theory multiple times, whether he did so because of social obligations or to try and make the lie more believable. Although Sheldon’s unusual behavior when lying was indistinguishable from his personality quirks for his friends, Sheldon most often capitulated after trying to build bigger and bigger lies so that he wouldn’t be discovered. This behavior was unmistakable in The Big Bang Theory season 3, episode 20 when Sheldon tried to hide his spending time with Penny to Leonard, and that he couldn’t to Penny, and the season 2 premiere, which transformed him into a mess with tics and almost made him move out.

Young Sheldon Seasons 1 & 2 Established Sheldon As A Capable Liar

While Sheldon’s refusal to be involved in lies was as staunch in The Big Bang Theory as in Young Sheldon, the prequel series highlighted multiple times how he excelled at it as a 9-year-old. Young Sheldon season 1, episode 9 introduced Sheldon to lying via Georgie, who taught him how to add details to make lies believable. Sheldon then managed to convince his P.E. teacher he had testicular hernia, stole from the library, and prompted Missy to destroy Meemaw’s garden to look for nonexistent money just so that he could have sole access to the TV, displaying an impressive ability to successfully lie without raising doubts.

Similarly, Young Sheldon season 2, episode 4 had Sheldon easily accept to keep George Sr.’s secret after he confessed it to Tam and released himself from the guilt of having to keep it. However, Sheldon made it clear how opposed he was to George’s request, eventually calling George out because his responsibilities as a parent shouldn’t have burdened Sheldon with such a secret. The episodes clearly highlight how if Sheldon thought logically about the purpose of getting out of what he didn’t want to do through lying, he would lie without problems and keep secrets successfully, only feeling burdened by the ethics and morality behind such a behavior.

Could George’s Affair Have Turned Sheldon Into A Bad Liar In TBBT?

How lies affected Sheldon differently in Young Sheldon and Big Bang Theory hints at a possible deeper meaning behind Sheldon’s difficulties with lying in TBBT. One difference between 9-year-old Sheldon and his adult iteration was the distressing witnessing of his father having extramarital relations and never talking about it with George even if his father knew Sheldon saw him, with the ordeal affecting Sheldon to the point that he didn’t share it with anybody before Penny in The Big Bang Theory season 10, episode 5. The secret was something Sheldon couldn’t process as George Sr. died right after the ordeal, leaving Sheldon burdened without a way to discuss it.

George’s cheating scandal will indubitably affect all the Coopers when it comes out, but based on Sheldon’s TBBT revelations, it would make sense for the younger Cooper brother to be so overwhelmed by it to have issues with lying because of the secret he had to keep. Coupled with the fact that Sheldon often created convoluted lies to make them believable in The Big Bang Theory, but their getting bigger and bigger would eventually make him come clean with the truth, it wouldn’t be too far-fetched that George’s affair in Young Sheldon will upset Sheldon so much that he will never be able to lie easily in The Big Bang Theory.