The concept of "Restraint" = bondage. It expresses the idea that a person's life is "ultimately ruled by time. In childhood, we are free from the constraints of time, but as we grow older, we are bound by the fetters of time. They try to free themselves from the fetters of time with their own hands, but they are bound by the time limit of their lifespan. These constraints of life and time are expressed as the beauty of natural events, not as negativity.