Kṛṣṇa is again designated as Hṛṣīkeśa. As we have explained several times, bhakti means hṛṣīkena hṛṣīkeśa-sevanaṁ bhaktir ucyate (CC Madhya 19.170). Bhakti, the whole devotional service program, means hṛṣīkena hṛṣīkeśa-sevanam. So Arjuna was meant for serving Kṛṣṇa, because he is bhakta. Kṛṣṇa has already addressed him, bhakto 'si, priyo 'si, rahasyaṁ hy etad uttamam: (BG 4.3) "My dear Arjuna, I am speaking to you the mystery of Bhagavad-gītā." It is a mystery. Mystery means very complicated; no ordinary man can understand. Therefore it is called mystery, rahasyam. But not ordinary rahasyam, uttamam. Uttamam means transcendental, not covered with darkness of material science. But it is brilliant, daivam, divyam. Rahasyam.
So ordinary man cannot understand. Therefore they interpret foolishly, speculate, and demonstrate their rascaldom. That's all. Even big, big scholars. So they cannot understand because they are not devotee. It is meant for the devotee. This whole Bhagavad-gītā is a transaction between God and His devotee. There is nothing more.