Why Young Sheldon's John Sturgis Doesn't Show Up In The Big Bang Theory

"The Big Bang Theory" lasted for 12 successful seasons, and during that time, the sitcom brought in several characters from Sheldon Cooper's (Jim Parsons) life. His mom, brother, and sister all show up for on-screen roles, and his deceased father gets a mention. That said, not everyone who impacted Sheldon gets acknowledged in the nerdy sitcom. Paige Swanson (McKenna Grace) from "Young Sheldon" doesn't appear on "Big Bang Theory," even though she was a notable part of his coming-of-age years, while Dr. John Sturgis (Wallace Shawn) is also ignored in spite of having dated Sheldon's Meemaw (Annie Potts) and mentored him.

Case in point: Sheldon's Nobel Prize speech in the "Big Bang Theory" finale made the cast cry, proving that it's an emotional moment. The scene sees the socially awkward physicist thank most of the important people in his life for supporting him throughout the years, marking a rare expression of gratitude from the character. However, Sheldon doesn't mention Sturgis during his big speech despite the influence he had on his childhood and scientific development back in the day. Keeping that in mind, there's one scene on "Young Sheldon" that suggests the titular boy genius doesn't respect Sturgis all that much, thus negating any need to mention him on "Big Bang Theory."

Sheldon Cooper is pretty self-centered throughout the entirety of "The Big Bang Theory." In fact, his aforementioned speech in the series finale is arguably the only time he realizes how lucky he is to have to have his friends. At the same time, it's hardly surprising that Dr. John Sturgis was omitted from his big moment, as Sheldon didn't always see eye-to-eye with his mentor.

In the "Young Sheldon" season 6 episode "Little Green Men and a Fella's Marriage Proposal," Iain Armitage's eponymous boy genius and Sturgis get into a disagreement over the concept of alien life. In a theory posited by ScreenRant, it's noted that Sheldon dismisses his mentor's ideas, which could have led to him losing respect for the veteran's scientific opinions. However, it's also strange that Sheldon didn't even mention him in a negative light on "Big Bang Theory," as he was known to overblow stories about people who upset him during his childhood, as evidenced by the times he recalled his old neighbor Billy Sparks (Wyatt McClure) being a bully, even though he wasn't.

That said, sometimes this franchise comes up with ideas and characters as it goes along, meaning that some of the finer details are overlooked. "Big Bang Theory" creator Chuck Lorre even regrets having killed George Cooper (Lance Barber) as it meant "Young Sheldon" was beholden to ideas introduced on its parent show. As such, it's entirely possible the spinoff's creatives wanted to avoid more unwelcome crossover elements between both series.