The mere process of growing old together will make the slightest acquaintance seem a bosom friend.

Smith’s aphorism observes how time itself manufactures intimacy. As people age alongside one another—sharing the same historical moments, social changes, and the gradual narrowing of life’s circle—mere familiarity can deepen into something that feels like friendship, even when the original relationship was slight. The line suggests that companionship is not always the product of deliberate emotional investment; it can be an unintended byproduct of duration and repeated proximity. It also carries a faintly ironic edge typical of Smith: what we call “bosom friendship” may sometimes be less a testament to profound affinity than to the human need for continuity and recognition as the years accumulate.