Don't let one cloud obliterate the whole sky.

The image contrasts a single cloud with the vastness of the sky to warn against letting one setback, sorrow, or irritation dominate one’s whole perception of life. It urges proportionality: acknowledge the “cloud” without allowing it to eclipse everything else that remains true, good, or possible. In this sense the line functions as a counsel against catastrophizing and emotional absolutism—habits that turn a momentary difficulty into a total verdict on one’s circumstances or self. The metaphor also implies transience: clouds pass, while the sky endures, suggesting resilience through a wider, steadier perspective.