The literal meaning is straightforward: if you can remain calm and unaffected by the constant stream of things you want, the external world's influences, and your own temper, you are in a state of well-being. This is the surface of the teaching.

The deeper esoteric meaning, as presented in the Bhagavad Gita, points towards the yogic path of detachment. Krishna is describing the state of a 'sthitaprajna' – one of steady wisdom. This state is achieved not by suppressing desires or emotions, but by understanding their impermanent nature and their origin in the ego (ahamkara). The material energies (prakriti) are seen as the play of the gunas (sattva, rajas, tamas) which create these disturbances. By recognizing your true self (Atman) as distinct from the mind and body, you are no longer tossed about by the waves of desire and aversion. This detachment is the key to liberation from the cycle of suffering (samsara), freeing you from the binding effects of karma generated by such reactions.

In your life: Observe your reactions to desires and frustrations without judgment. Recognize that these feelings arise and pass, and your true self remains untouched by them, like the sky unaffected by passing clouds.