What is equanimity? How to have a devoted mind?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

सम: शत्रौ च मित्रे च तथा मानापमानयो: ।

शीतोष्णसुखदु:खेषु सम: सङ्गविवर्जित:। । 18 । ।

तुल्यनिन्दास्तुतिर्मौनी सन्तुष्टो येन केनचित् ।

अनिकेत: स्थिरमतिर्भक्तिमान्मे प्रियो नर: । । 19 । ।

samaḥ śhatrau cha mitre cha tathā mānāpamānayoḥ

śhītoṣhṇa-sukha-duḥkheṣhu samaḥ saṅga-vivarjitaḥ

tulya-nindā-stutir maunī santuṣhṭo yena kenachit

aniketaḥ sthira-matir bhaktimān me priyo naraḥ

He who is the same to friend and foe, and also in honour and dishonour, who is the same in heat and cold, and in pleasure and pain, who is free from attachment; to whom censure and praise are equal; who is silent, content with anything, homeless, steady minded, full of devotion, that man…