Warning! Spoilers ahead for Young Sheldon season 5.
Young Sheldon inadvertently retcons a detail related to Howard Wolowitz (Simon Helberg) in The Big Bang Theory. Sheldon's (Jim Parsons) engineer/astronaut friend was the latest character from the original sitcom to appear in the prequel spin-off. His guesting resulted in Sheldon explaining why he hates engineering so much. But not long after this revelation, Young Sheldon poses another question regarding Sheldon's relationship with Howard.
The socially-inept genius never missed the chance to boast about his intellectual prowess, and in the process, he invalidated other people's achievements. His friends were typically his victims, but no one suffered more of his mocking than Howard. For years, it was presumed that Sheldon looked down on him because he has no Ph.D. and isn't in the field of physics like him, Leonard (Johnny Galecki), and Raj (Kunal Nayyar). But, Young Sheldon season 5, episode 7, titled "An Introduction to Engineering and a Glob of Hair Gel" revealed that it wasn't as simple as that. The truth is, Sheldon, hates engineers because he struggled in his engineering class in college.
With that settled, many thought the mystery about Sheldon bullying Howard has already been resolved. But, Young Sheldon season 5, episode 8 titled "The Grand Chancellor and a Den of Sin" posed a brand new question regarding the pair's relationship. In the outing, Sheldon (Iain Armitage) cited MIT as the school he hates the most. He didn't provide any explanation why, however. In The Big Bang Theory, adult Sheldon usually ragged on the prestigious school, but there was an assumption that it's because Howard studied there. However, since Sheldon hasn't met his engineer friend at this point in the timeline, it's curious why he's already prejudiced against MIT at this point in time. Young Sheldon hasn't given any indication about this until he mentioned this to East Texas Tech's president, effectively retconning the idea that Sheldon only hated MIT because it's Howard's alma mater.
For what it's worth, Sheldon looked down on Ivy League institutions in The Big Bang Theory. But, he didn't seem to have such negative opinions of them in Young Sheldon. In fact, when Harvard and Princeton tried to recruit him for college, he was excited and more than willing to take their offers. The only reason he didn't go was because Mary (Zoe Perry) didn't want him to move out. As a compromise, Sheldon agreed to go to East Texas Tech for college so he could still live with his family. It's possible that Sheldon has such a strong distaste for MIT simply because it's one of - if not the best - engineering schools in the country, so he associates the field of study with the university. But Young Sheldon hasn't implied that this is the case. Perhaps the spin-off sequel can properly address this moving forward. After all, Young Sheldon has already been renewed until season 7, giving it plenty of time to address the matter.
Howard's recent appearance in Young Sheldon revealed the real reason why Sheldon hates engineers. But despite this, the cameo was a massive disappointment compared to previous guest appearances from other The Big Bang Theory cast members. This new mystery surrounding Sheldon's hatred of MIT is yet another reason why the spin-off sequel needs to bring back Howard in the future.