Warning! Spoilers ahead for Young Sheldon season 6, episode 13. Young Sheldon has created many plot holes, but this time, it has broken The Big Bang Theory's timeline, and in the process, its own. As Young Sheldon progresses, it also moves the canon that was established by its parent series. While its weekly storylines don't really impact the continuity, Jim Parsons' narration as adult Sheldon allows CBS to emphasize their connection. However, in Young Sheldon season 6, episode 13, the voiceover raises some questions about where the prequel currently lands in The Big Bang Theory timeline.
CBS has understandably kept Young Sheldon's time setting vague. However, several details in the family sitcom indicate that it's now 1993, which means that George's impending death is close. At this point, both Missy and Sheldon are about to turn 13 years old (depending on the month). While that all checks out with regard to the prequel's timeline, a comment from adult Sheldon's narration creates a The Big Bang Theory problem with regard to the character's supposed age in the future.
Young Sheldon Makes Adult Sheldon’s Age Confusing
During Amy's surprise guest appearance in Young Sheldon season 4, the genius talked about his son, Leonard Cooper's high school graduation. This means that at the very least, adult Sheldon would be in his early 50s since he was 39 years old when he won the Nobel Prize in Physics in The Big Bang Theory finale. That's assuming that he and Amy immediately got pregnant after their academic achievement. However, in his comment in Young Sheldon season 6, episode 12, he revealed that it has just been 30 years since Missy convinced him to look after passed out Paige. That makes adult Sheldon only 42/43 years old,
Given this, it's just impossible that Sheldon would be able to talk about his and Amy's son graduating from high school because he wouldn't be old enough to properly start his education. Even if Leonard Cooper is a genius like his parents and was born a year after The Big Bang Theory finale, there's no way that he would have been able to finish secondary school at this rate. Unfortunately, since this incident was never mentioned in the nerd-centric sitcom and Young Sheldon didn't dwell on the story, it's a new issue that CBS would need to address moving forward.
There’s An Easy Fix To Young Sheldon’s TBBT Timeline Plot Hole
While it would still be better if Young Sheldon totally ignores TBBT, there's an easy fix to this timeline kerfuffle. CBS can simply say that adult Sheldon's narration isn't in chronological order. It's still unclear why adult Sheldon is recounting certain events from his childhood. However, if the theory that he is working on an autobiography following his Nobel win in The Big Bang Theory finale turns out to be true, then it's possible that he is telling these stories out of order. Perhaps he just sticks to whatever he remembers that particular day.
Young Sheldon season 6 airs Thursdays on CBS.