Answer:
The central idea of the poem is that people build bridges between themselves through customs that are traditional.
Step-by-step explanation:
In "Mending Wall" by Robert Frost, we learn of two neighbors who are separated by a wall they built in between themselves. The narrator who is one of the neighbors noted that these walls served as obstacles to the unity or friendship that should exist between neighbors. He however noted that his neighbor did not share his views for when he asked him why they had to build the wall between themselves since they had no pets that the wall could have helped to manage, the neighbor replied in this words:
"Good fences make good neighbors"
These words were passed to him by his father who saw this disposition as a normal tradition for peace between neighbors.