There is a saying that goes: 'The comfort of twilight years is foreshadowed at fifty-five.' It implies that the ease of someone's later years is often indicated by the time they reach the age of fifty-five. Fifty-five is a milestone in the journey of life—although one is still in their middle ages, the outline of old age has subtly begun to emerge. By then, one should learn to live like a sparrow, capable of building nests in the crevices of towering skyscrapers, foraging on the lofty treetops, and even finding everything they need in abandoned nooks... This is the illustrious 'Sparrow Principle'.