Bhagavad Gita
Chapter 6 · Verse 35
असंशयं महाबाहो मनो दुर्निग्रहं चलम्। अभ्यासेन तु कौन्तेय वैराग्येण च गृह्यते॥
asaṁśayaṁ mahā-bāho mano durnigrahaṁ calam, abhyāsena tu kaunteya vairāgyeṇa ca gṛhyate
An honest acknowledgment that stillness of mind doesn't come easily for anyone, followed immediately by reassurance that it's still within reach.
The restless mind can be tamed through patient practice and letting go.