Chapter 6 · The Yoga of Meditation · Krishna said
Bhagavad Gita 6.35 — Practice and detachment
श्रीभगवानुवाच। असंशयं महाबाहो मनो दुर्निग्रहं चलम्। अभ्यासेन तु कौन्तेय वैराग्येण च गृह्यते ॥
śrībhagavānuvāca | asaṃśayaṃ mahābāho mano durnigrahaṃ calam | abhyāsena tu kaunteya vairāgyeṇa ca gṛhyate ||
Meaning
Krishna says: No doubt, mighty-armed one, the mind is restless and hard to control. But it can be mastered by steady practice (abhyas) and detachment (vairagya).
In today's life
Don't lose heart when the mind wanders — small daily practice and a little distance from needless distractions slowly train it.