When Fortune smiles, I smile to think how quickly she will frown.

The line treats “Fortune” as a capricious person whose favor is inherently unstable. The speaker’s smile is not simple delight but a wry, disciplined response: prosperity is enjoyed with the awareness that reversal is near. In this way the quote expresses a moral stance akin to Christian and Stoic admonitions against trusting worldly success—gratitude without attachment, and readiness for loss. Its compact antithesis (smiles/frown) underscores the volatility of external circumstances and recommends interior steadiness rather than dependence on luck.