One day a man saw a butterfly shuddering on the sidewalk, locked in a seemingly hopeless struggle to free itself from its now useless cocoon. Feeling pity, he took a pocket knife, carefully cut away the cocoon, and set the butterfly free. To his dismay, it lay on the sidewalk, convulsed weakly for a while, and died.
A biologist later told him, "That's the worst thing you could have done! A butterfly needs that struggle to develop the muscles to fly. By robbing him of the struggle, you made him too weak to live."