How did Ishmael Beah's grandmother explain the local adage that "we must strive to be like the moon"?

When an old man encourages Beah that they should “be like the moon”, he asks his grandmother what this means. She explains that even though people complain when the sun shines too brightly, no one is annoyed by the brightness of the moon. Good things happen when the moon is full and its light is at its greatest.