Krishna has been tracing the sequence from sense-contact to ruin. Here he gives the sharpest single image of that sequence: the wind and the boat on water.
indriyāṇāṃ hi caratāṃ yan mano 'nuvidhīyate | tad asya harati prajñāṃ vāyur nāvam ivāmbhasi ||
Among the senses that are roaming outward, whichever one the mind follows along with, that sense carries away his wisdom, just as the wind carries a boat on water.
The previous verses laid out the chain: contact leads to desire, desire to anger, anger to confusion. This verse is the turning point in that chain. It identifies the exact moment of loss: when the mind follows the sense. Everything before that is still recoverable. After that, prajñā is gone and you are operating on autopilot.
The verse says 'whichever one' (yat). Not all of them, not several. One sense pulling one time is enough to do the damage. This makes the teaching uncomfortable because it closes a common escape: 'I was handling it well overall.' One unguarded thread is all it takes.
This is the cruel irony. When the wind takes the boat, the boat does not experience itself as lost. It is simply moving. When the mind follows a sense and prajñā is carried off, the person does not feel stupider. They just keep acting from the diminished state, convinced they are still seeing clearly.
Krishna is not saying: get the boat out of the water, or stop the wind. He is pointing at what happens when there is no rudder in the water. The senses will keep moving, the winds will keep blowing. The question is whether there is a steady interior that holds direction. That steady interior is what the whole second chapter is building toward.
Person A sits down to do deep work. Notification appears. They don't open it, but the mind has already moved toward it. A minute later they are reading the thread. Twenty minutes later they have lost the thread of their own thinking entirely and can't remember what they were trying to solve. They feel like they just got distracted. What actually happened is in this verse. Person B notices the notification, notices the small pull toward it, and watches the mind start to follow. That noticing creates just enough gap. The mind doesn't follow all the way out. They return to the work. The clarity stays intact. Not because they are more disciplined. Because they caught the moment of 'anuvidhīyate': the mind beginning to comply.
Verse 2.68 delivers the conclusion Krishna has been building toward: the person whose senses are withdrawn from their objects has steady wisdom. It is the positive completion of what this verse diagnoses in the negative. When ready, say: "2.68"