Acharya Prashant explains that the fundamental difference between one who suffers and one who does not lies in the presence of something beyond pain. Pain is a physical or circumstantial condition, whereas suffering is the mental state of having nothing larger than that pain. He uses the analogy of a bank account: if a person with a zero balance loses a hundred rupees, they are left with a negative balance, which represents suffering. However, a person with a vast fortune who loses the same hundred rupees remains essentially unaffected because the loss is insignificant compared to their total wealth. Therefore, suffering arises not from the loss itself, but from the lack of an inner 'immensity' or fullness that makes the loss seem trivial.