The most useless are those who never change through the years.

Taken at face value, the line argues that a life without growth—without revising one’s views, habits, or sympathies in response to experience—amounts to a kind of social and moral stagnation. “Useless” here is less about productivity than about human value in relation to others: a person who never changes cannot learn, adapt, or deepen, and so contributes little to the evolving needs of a community. Read alongside Barrie’s recurring interest in youth, maturity, and the costs of refusing development, the remark can be heard as a warning against complacency and self-satisfaction: time will change the world regardless, and refusing to change with it is a choice to become irrelevant.