P.G. Wodehouse's quote highlights the captivating power of a girl's smile, suggesting that it can inspire transformation in those around her. It likens a smile to a raisin mixed with yeast, implying that it has the ability to awaken feelings and energies that might otherwise remain dormant. This metaphor emphasizes the enchanting and uplifting effect a girl's joy can have on a man's state of mind and demeanor.

The author celebrates the subtle yet profound influence of a woman's charm. The comparison to yeast suggests that a simple smile can spark something greater, leading to unexpected joy and enthusiasm. Wodehouse recognizes the significance of such simple gestures, reflecting on how they can dramatically alter the emotional landscape of individuals, particularly in a social context.