We are like butterflies who flutter for a day and think it is forever.

The image contrasts the brevity of an individual human life with the vastness of time. Like a butterfly with a lifespan of only a day, we can mistake our immediate experience—our personal memories, cultural moment, and historical era—for something permanent. The quote underscores a central Sagan theme: humility before cosmic timescales and the danger of parochial thinking. It invites a shift in perspective: to recognize how fleeting our lives are, and therefore to value knowledge, compassion, and stewardship (of one another and of Earth) precisely because our moment is short.