Human beings have been in the grip of miseries for eons-ever since they fell from their original state, entered the realm of time and mind, and lost awareness of the self and the Supreme. Since then, they have been trying to lord it over this material world.
Suffering is inevitable as long as one identifies with the mind and body, i.e., as long as one is unconscious, spiritually speaking. Suffering is not only due to external agents. Our inner feelings of resentment, hatred, anger, depression, jealousy, and so on are all forms of suffering. And every pleasure contains within itself the seed of pain: each an inseparable opposite, which will manifest in time. Many people also know from their own experience how easily and quickly an intimate relationship can turn from a source of pleasure into a source of pain. Seen from a higher perspective, both the negative and positive polarities are two sides of the same coin; they are both part of the underlying pain that is inseparable from the mind identified with the egoistic state of consciousness.