According to the Gītā, life in the material world is temporary. The four things that we experience here are birth, death, old age and disease. Any happiness we may experience here is impermanent and ultimately leads to more suffering. True happiness in life can only be achieved when one understands his natural position as ātmā and surrenders to Kṛṣṇa. Understand more about the cycle of birth, death, old age and disease in Bhagavad-gītā Chapter 13 – Prakṛti-Puruṣa Viveka Yoga (The Yoga of Differentiation) – Verses 8-12 and the Anuvṛtti