Answer
Because intellectual understanding alone cannot overcome deeply conditioned feelings and perceptions.
Human behavior is driven not only by thought but by bundled patterns of thinking and feeling. We see according to how we feel, and we act according to how we see. These bundles become what may be called deep impressions or emotional convictions (bhavana).
Take the example of attraction to the opposite sex. Through repeated material conditioning, a particular way of seeing and feeling becomes tightly bound together. Even after hearing from Prabhupada that we are not the body and that the soul is neither male nor female, the old emotional pattern remains active.
The solution is not merely suppressing behavior, but creating a new perception.
One must deliberately cultivate a Krishna conscious way of seeing:
See the soul, not merely the body.
See all beings as connected to Krishna.
See everything as meant for Krishna's service.
This requires a process of contemplation. It is not enough to hear the truth once. You must repeatedly contemplate it and apply it in real relationships and situations.
First comes knowledge, then contemplation, and then emotional transformation. The intellect must repeatedly remind the mind of reality until a new emotional pattern is formed.
Just as conditioned perception was created through repeated wrong thinking and feeling, it can be replaced by repeated right thinking and right feeling. Eventually, Krishna conscious perception becomes the new default.
Pure devotees do not struggle in the same way because their perception has already become purified. They naturally see the soul, the body, and the Supersoul distinctly.
In the spiritual world, there is no struggle to control the senses because perception is perfectly aligned with reality. The struggle exists only because our present perception is distorted by material conditioning.
The practical method is to train the mind to see everything according to guru, sadhu, and shastra. Everything belongs to Krishna, everything is meant for His pleasure, and every relationship should be understood in connection with His service.
For example:
Money is Krishna's property and should be used in His service.
Men and women are eternal souls who should be related to according to dharma and service.
Association should be carefully regulated because hearing another person's mind creates subtle association.
Especially with the opposite sex, unnecessary emotional intimacy begins through hearing and sharing personal mental stories. Therefore, one should maintain appropriate boundaries and remain focused on Krishna and one's devotional service.
The more one lives in the world of service, prayer, remembrance, and devotion, the less one's mind becomes filled with unnecessary material stories. Gradually, Krishna conscious perception replaces material perception, and the struggle to control the senses diminishes naturally.
