9. Will Sheldon Change Any More?
When we first met Sheldon, he came across as someone who you could be easily annoyed by, something that he can't actually help in fairness. In the 278 episodes that came after that pilot though, we saw him go through several changes in terms of his personality and his attitude towards friends, family, and peers.
By the time the finale aired, Sheldon had become more open in his relationship with Amy, being less reluctant when it came to holding her hand and hugging her. In addition, the finale episode saw Sheldon accept his Nobel Prize with a speech that saw him thank Amy and the rest of his friends as opposed to a self-centred speech that he had previously prepared. The Sheldon of Season 1 would have used the second speech without even thinking about it.
Despite how much he had changed over the 12 seasons, there are still certain aspects of Sheldon's personality that could've changed had there been more seasons commissioned. Things such as being unable to cope with the prospect of gift giving could easily change - he still has plenty birthdays and Christmases in his future in order for that to be a possibility.