In many stories featuring a conflict between a narrator and an old man, the tension often arises from factors such as differing perspectives, generational gaps, or moral dilemmas. A common theme might involve the narrator's desire for change or independence clashing with the old man's traditional values or resistance to change. This conflict may also stem from personal grievances, misunderstandings, or the old man's behavior that the narrator finds troubling or oppressive.
For example, in Edgar Allan Poe's "The Tell-Tale Heart," the conflict revolves around the narrator's obsession with the old man's eye, which he perceives as a source of evil. The internal struggle of the narrator, combined with psychotic tendencies, leads to dire consequences.
If you provide the specific story you had in mind, I can give a more tailored explanation of the conflict between the narrator and the old man.