Avajānanti māṁ mūḍhā mānuṣīṁ tanum āśritam, paraṁ bhāvam ajānantaḥ (BG 9.11). They do not understand the background of Kṛṣṇa. So this thing is being clarified by the question of Arjuna, aparaṁ bhavato janma. "You are born along with me. You are my contemporary." And paraṁ janma vivasvataḥ, "And the sun-god, or the president of the sun, Mr. Vivasvān, he's long, long ago. How can I believe that You talked with him?" This is the question. Aparaṁ bhavato janma paraṁ janma vivasvataḥ, katham etad vijānīyām (BG 4.4). "How I shall believe it?" Yes. This is possible, to inquire like that. Tvam ādau proktavān iti. "You first of all spoke this." This is the difference between God and the living entity. The . . . God does not forget. We forget. This answer will be in the next verse: bahūni me vyatītāni janmāni tava cārjuna tāny ahaṁ veda sarvāṇi (BG 4.5), "I understand. I know everything." In another place Kṛṣṇa . . . that, "I know the past, present, future." That is knowledge.
Knowledge means, perfect knowledge means past, present and future. There are many foretelling in the Śrīmad-Bhāgavatam about this Kali-yuga. They are stated in the Śrīmad-Bhāgavatam. Means future . . . Śrīmad-Bhāgavatam was written five thousand years ago. Still, what was stated at that time, they're coming to be true. That is called śāstra. Past, present and future. So Kṛṣṇa knows everything. Vedāhaṁ samatītāni (BG 7.26). He says that, "I know everything, past, present and future." That is perfect knowledge. Why you are hankering after Kṛṣṇa? Because He is perfect. We are not perfect. We have got so many deficiencies: we commit mistake, we are illusioned, we cheat and our senses are imperfect. We cannot acquire knowledge by sense perception perfectly. So with so many imperfectness, if we try to become a teacher, then I am a cheater. I am not a teacher. We must know first of all. So we are receiving knowledge from Kṛṣṇa because Kṛṣṇa is accepted the Supreme Personality of Godhead and with perfection of knowledge.