It is true that everyone saves a drop of water, and not just himself. However, many a mickle makes a mickle. "If everyone in the world doesn't save a drop of water, it's useless for me to save!" A little reactionary. A drop of water is not small, it is worth cherishing. A drop of water can make a person live longer on the edge of thirst. A drop of water is especially important in the desert, isn't it?