OP here, didn't expect to actually get published! Backstory, it's a college Intro class that I have to take before I can branch off into the Fiction classes (it's my major with intent to teach Fiction writing myself at university level). My professor has a PhD in Poetry. The first half of the class was poetry, and this last half of the semester is fiction. The problem is she has no interest in seeing her fiction-oriented students succeed, and from her feedback on my stories, I'm fairly certain she's not even reading them from feedback like not being able to tell two different characters with different names were not the same person. But I digress. The student's story we were workshopping was about an nonathletic person going mountain climbing with his athletic friend, Charles. Charles spends the whole story pushing the protagonist forward and encouraging him, "You can do it!" and "We're almost there!" She tried to tell us Charles HAD to be the antagonist because he was the only other character in the story. So I called her out and told her the antagonist is whatever force that drives the conflict forward, as well as explaining the concept of Man vs Man, Man vs Self, Man vs Nature, etcetera. This woman is a college professor for fucks sake.