Bhagavad Gita

ಭಗವಾನುವಾಚ ।
ಪ್ರಜಹಾತಿ ಯದಾ ಕಾಮಾನ್ ಸರ್ವಾನ್ ಪಾರ್ಥ ಮನೋಗತಾನ್
ಆತ್ಮನ್ಯೇವಾSತ್ಮನಾ ತುಷ್ಟಃ ಸ್ಥಿತಪ್ರಜ್ಞಸ್ತದೋಚ್ಯತೇ ॥೫೫॥
bhagavānuvāca |
prajahāti yadā kāmān sarvān pārtha manogatān
ātmanyevāStmanā tuṣṭaḥ sthitaprajñastadocyate ||55||

Gist of the sloka:
O Partha, one who has removed all desires from his mind, and has stationed his mind, thoughts and actions in the Lord; and one who has obtained the Lord grace is called stithapragna.
Lord Krishna describes the person who has achieved state of stitha-pragna who have removed all desires [desires which lead the person astray, not the desire which one might have to achieve God realization]. He would no longer be bothered with external material comforts for he would be happy with his inner bliss where he is able to see the Lord in all glory.
The main reason for a man’s grief is his wrong desires. There is no end to it either. If and when the desired result does not happen, he gets anger. Anger leads him to undertake actions which leads to papha. This leads to mental states which does not allow him to towards true knowledge but leads him to Hell. He would have no idea about the powerful force which resides in him.
One who has reached the state of stitha-pragna would have none of the above problems. He would have no desires of the outside world. He would be quite happy with his inner bliss and have a sense of detachment with the outside world. The happiness he gets internally is many million times more intense than the one obtained from outside world. He would forever be happy. He would not lose his mental stability even when facing great difficulties. He would be mental strong and un vacillating. Therefore, he succeeds.
Lord Krishna calls Arjuna ‘Partha’. In Sanskrit, the word would split as paara-theera-gamanae. One who has swam across the ocean and reached the shores of knowledge/truth. Lord is indicating that Arjuna should have known this fact beforehand.
The next 3 verses indicate how one should remove unwanted desires.