Mind Control
Bhagvadgita Chapter 6 Verse 6:
bandhur aatmaat manah tasya
yenaat mai vaatmanaa jitah
anaath manas tu shatrut ve
vartetaat maiva shatruvat
Mind is a friend of the self, for one who has conquered it and has it in control. It will behave as one of the worst foe to self, to one who has not controlled mind.
Bhagvadgita Chapter 6 Verse 7:
jitaat manah prashantasya
pramaatma samaahitah
shitosna sukha dukheshu
tathaa mananapa maana yoh
The mind of whom is conquered and in control he would have achieved traquility with the Supreme. For that person happiness and distress, heat and cold, honour and dishonour are all the same.