यततो ह्यपि कौन्तेय पुरुषस्य विपश्चितः।इन्द्रियाणि प्रमाथीनि हरन्ति प्रसभं मनः॥
yatato hyapi kaunteya puruṣasya vipaścitaḥindriyāṇi pramāthīni haranti prasabhaṃ manaḥ
Word by word
The verse says
The senses are violent, Arjuna. They will carry off the mind by force - even the mind of a clear-sighted person who is working at it.
In plain words
And now an even blunter admission.
Even someone who understands, and is genuinely trying, gets overpowered. The word is prasabham - by force, violently.
This is not addressed to beginners. It is about the person who is already doing the work.
Where you've felt this · in failure
You know exactly what sets you off and you have a plan for it. Then it happens on a bad day, and you watch yourself walk straight down the path anyway, understanding perfectly well what you are doing.
Going deeper
Vipaścit - discerning, clear-sighted, wise. Krishna is explicitly saying that knowledge does not confer immunity.
This verse rescues the whole portrait from being a shaming device. Everything from 2.55 to 2.58 described a finished person, and a reader could reasonably conclude that failing to match it means failing entirely. Verse 60 heads that off. Being carried away is what happens, including to people far along the road.
Pramāthīni is a striking word for the senses: turbulent, churning, agitating. Not evil, and not to be destroyed. Powerful and hard to steer.
The Gita's attitude to the body is worth noting here, because it is often misdescribed. The senses are never treated as enemies to be mortified. They are treated as strong horses - which is the image the Katha Upanishad uses and the one implied by Arjuna's chariot.
Strong horses are not a problem. Strong horses with nobody holding the reins are. And the next verse says who is holding them.