Sheldon tells Mary, "You have your stories; I have mine." But Mary flipped this on him decades later in The Big Bang Theory. Specifically, Young Sheldon's Mary asked whether Sheldon believed in aliens, and when he said he did, she wondered if these aliens were Christian. This prompted his pithy retort, which came back to bite him in The Big Bang Theory season 3, episode 1, "The Electric Can Opener Fluctuation," when Mary stated that everyone is entitled to their opinion. Sheldon said that evolution wasn't an opinion but rather a fact.
Despite Sheldon's characteristic bluntness, Mary immediately replied, "And that is your opinion," a retort that effectively repackaged his "you have your stories, I have mine" comment a generation later.
While Mary and Sheldon may have divergent worldviews, this doesn't necessarily mean they are very different characters. In Young Sheldon and The Big Bang Theory, Mary and Sheldon believe in totally opposing ideologies, but they are similarly dogmatic and obstinate. As Mary's infamous line in The Big Bang Theory proves, there were also times when Young Sheldon's hero inadvertently inspired his mother over the years.
