A rolling stone gathers no moss.

The proverb warns that constant movement prevents accumulation—whether of wealth, reputation, skills, or social ties. “Moss” can be read positively (security, experience, rootedness) or negatively (stagnation, complacency), so the saying has been used both to praise steadiness and to criticize restlessness. In moralizing traditions it often implies that a person who never settles cannot build lasting advantages; in other contexts it is inverted to suggest that continual change keeps one “clean” of dull routine. Its durability comes from this ambiguity: it can counsel stability or celebrate mobility depending on the speaker’s values.