Just like Arjuna is following strictly. He has first of all submitted to Kṛṣṇa. Śiṣyas te 'haṁ śādhi māṁ prapannam: (BG 2.7) "My dear Kṛṣṇa, we are talking friendly, so on equal level. So You will speak something, and I shall speak something. In this way we shall simply waste our time, and there will be no conclusion. Therefore, I submit as disciple. Whatever You will say, I will accept."
This is the first condition. First of all find out such person whom, upon whom you have full faith that whatever he will say, you will accept. That is guru. If you think that you know better than your guru, then there is no use. First of all you find out the person that one who is better than you. Then you submit. Therefore the rules and regulation are that nobody should accept blindly any guru, and nobody should blindly accept any disciple. They must behave, one another, at least for one year so that the prospective disciple can also understand, "whether I can accept this person as my guru," and the prospective guru also can understand, "whether this person can become my disciple." This is the instruction by Sanātana Gosvāmī in his Hari-bhakti-vilāsa.
So here Arjuna has accepted Kṛṣṇa as his guru. And he submissively says that prakṛtiṁ puruṣaṁ caiva. Prakṛti, prakṛti means nature, and puruṣa means the exploiter of the nature. Just like here in this material world, especially in the Western countries they are very much fond of developing undeveloped countries. That means exploiting, or to become puruṣa, enjoyer. You Americans, you came from Europe, and now you have developed the whole America, very nice cities, towns, and very well developed. That is called the exploiting the resources.