Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.

The saying contrasts two social types: those who diminish others’ aspirations to protect their own sense of superiority, and those whose confidence and generosity enlarge the ambitions of people around them. It functions as advice about choosing one’s company—treating encouragement as a marker of genuine greatness and chronic disparagement as a sign of insecurity. Although widely circulated under Twain’s name, the sentiment aligns with a broader moral commonplace in self-help and character writing: ambition is socially contagious, and environments of respect and high expectation can help individuals grow into their capacities.