Young Sheldon inadvertently explains one of the biggest mysteries from The Big Bang Theory series finale: Why Sheldon didn't thank Dr. Sturgis in his Nobel Prize in Physics acceptance speech? While much of the previous episodes in season 4 focused on the socially-inept genius spending his summer break, Young Sheldon's latest episode began his preparation for college.
In Young Sheldon season 3, Sheldon, with the help of his father, George Sr., successfully convinced Mary to let him go to college early. This was after he unexpectedly discovered that prestigious universities around the country had expressed interest in taking him, including his future workplace, CalTech. As a compromise, Sheldon proposed that he attend East Texas Tech instead, mainly due to its proximity, but also because he was already working with one of the school's most esteemed professors, Dr. Sturgis, who also happens to be the person who got him into physics. So, it's puzzling why Sheldon didn't mention him when he accepted the Nobel Prize in Physics for his and Amy's work on Super Asymmetry in The Big Bang Theory finale.
This question was answered in Young Sheldon season 4, episode 6, "Freshman Orientation and the Inventor of the Zipper" where Sheldon headed to East Texas Tech for his college orientation. Of course, his day didn't go according to plan, as not only was he late for his session but he also went in there with a Slurpee-stained shirt and a busted zipper held together by duct tape. To make matters worse, it's also revealed that Dr. Sturgis took a job at Superconducting Super Collider, forcing him to move to Waxahachie, Texas. This was unexpected, leaving Sheldon without any adult or companion in East Texas Tech. Granted, Dr. Sturgis still is in Texas, but this essentially halts Sheldon's mentorship as they most likely sever all communication, except for occasional phone calls. So while he was instrumental in Sheldon's early days of dabbling into physics, this separation will undoubtedly impact their relationship, to the point that Sheldon didn't think Dr. Sturgis warranted a special mention in his Nobel Prize acceptance speech.
Aside from this, it's also possible that Sheldon may have been harboring a secret grudge against Dr. Sturgis for abandoning him. It's worth noting that he was a major proponent for Sheldon attending college early, and it would be understandable if Sheldon felt let down by his sudden departure. As revealed in The Big Bang Theory, there were certain key players from his past that he intentionally didn't mention to his Pasadena gang, because he wrote them off for something they did to him. This was exactly what happened to Tam, Sheldon's first best friend in Texas as revealed in Young Sheldon. To establish a connection between the shows, The Big Bang Theory brought in an adult version of the character where it was revealed that Sheldon never talked about Tam, because he's still mad at him for refusing to move with him to California, instead, choosing to stay behind with his girlfriend.
While this explains Dr. Sturgis' non-mention in Sheldon's speech after winning the Nobel Prize, this wasn't the biggest plot hole from The Big Bang Theory finale, unfortunately. The fact that Sheldon's family - Mary, Georgie, Missy, and Meemaw - weren't at the ceremony was more problematic. Perhaps like this one, they can provide some answer regarding this still pressing question through a future episode of Young Sheldon.