Kṛṣṇa defines the roles of matter and spirit. Nature (Prakṛti) is the cause of all physical activities, causes, and effects. It provides the machinery. The living entity (Puruṣa) is the cause of the experience—the feeling of happiness and distress. Nature builds the roller coaster; the soul feels the thrill or the fear. This verse explains why we feel responsible for our lives. While our bodies act according to the laws of physics and biology, our experience of those actions belongs to us. We are the ‘Bhoktṛ’ or the enjoyers and sufferers of our situation. We provide the desire, and nature provides the facility. Understanding this distinction helps us stop blaming God or others for our suffering. We realize that while the body follows material laws, our internal state is our own responsibility. By changing our consciousness, we can change our experience of the world, even if the material ‘machinery’ remains the same.