श्रीभगवानुवाच |
प्रजहाति यदा कामान्सर्वान्पार्थ मनोगतान् |
आत्मन्येवात्मना तुष्ट: स्थितप्रज्ञस्तदोच्यते ||2.55||

śhrī bhagavān uvācha
prajahāti yadā kāmān sarvān pārtha mano-gatān
ātmany-evātmanā tuṣhṭaḥ sthita-prajñas tadochyate

The Supreme Lord said: O Partha, when one discards all selfish desires and cravings of the senses that torment the mind, and becomes satisfied in the realization of the self, such a person is said to be transcendentally situated.

Contentment is the key to self-realization and liberation. 

kṛṣṇadaasa
(Servant of Krishna)