In the world of dreams the rules of reality do not necessarily apply. Each dream is unique and it's a direct link to the soul and spirit. Psychology provides its own theories on what dreams mean, but so did tradition and the study of dreams for thousands of years before any relevant science had developed.
Dream Meanings - Rock
If you see rocks falling on your house then you will have difficulties, but if rocks fall on top of you then you will be shaken by something. If you dream of a rock then some obstacles in your life will make you anxious.