Grief is the child of the disease created by desire. Happiness again comes when the disease of desire is cured. From joy originates sorrow, and sorrow comes again and again.
तृष्णार्तिप्रभवं दुःखं दुःखार्तिप्रभवं सुखम्। सुखात् संजायते दुःखं दुःखमेवं पुनः पुनः॥