Chapter-2, Verse 16

Ashtavakra Gita Verse 2.16

द्वैतमूलमहो दुःखं नान्यत्तस्यास्ति भेषजम्। दृश्यमेतन्मृषा सर्वं एकोऽहं चिद्रसोऽमलः॥१६॥

16. O! The root of all misery is the sense of duality. There is no other remedy for this (misery) except the Realisation that all visible objects of experiences are unreal and that I am the non-dual, Pure Consciousness and Bliss. 

Misery, pain or sorrow, are all subjectively nothing but mental states of disturbances. The more the mental agitations, the more the sorrow. Quieter the mind, happier the man. These disturbances are caused by the mind's perceptions of the pluralistic world, both within itself and outside. 

All miseries stem forth from the perception of duality. With the Realisation of one's own nature to be Pure, non-dual Consciousness, the world of plurality will be recognised as unreal and, therefore, it can no longer contribute any miseries to the Man of Realisation. In fact, there is no other remedy for this continuous sense of sorrow and misery at the ego plane of Consciousness (na anyat tasya asti bheṣajam).