Final answer:
The speaker is confused by the neighbor's dedication to rebuilding a wall between their properties, prompted by the adage "Good fences make good neighbours," which represents a traditional view on boundaries in relationships.
Step-by-step explanation:
The speaker in Robert Frost's poem Mending Wall is perplexed by their neighbor's insistence on repairing a wall between their properties every year. The speaker questions the usefulness of the wall, noting that nature itself seems to oppose its existence. The neighbor persists, however, repeating the adage, "Good fences make good neighbours." This refrain suggests a traditional belief in the value of boundaries in maintaining harmonious relationships. The neighbor's adherence to this saying without deeper reflection symbolizes a resistance to change and a clinging to the past, as seen with phrases such as "He will not go behind his father's saying," indicating generational influence. Frost uses the wall as a metaphor for the artificial barriers that people erect in their relationships, thus exploring themes of communication, tradition, and the natural world.