Don’t I Know You?
During the film Star Trek II: The Wrath of Khan, Chekov gets in an altercation with Khan. Their dialogue suggests they had met each other before in season one’s “Space Seed.”
However, hardcore fans are quick to point out that Chekov didn’t appear until season two. It’s quite a large writing blunder that still sits with fans the wrong way. However, it’s the next Khan scene still bothers fans to this day.