Just like I am cognizant, you are also cognizant. But I do not know myself, how many hairs are there in my body. I'm claiming this is my head. But If ask anybody, "Do you know how many hairs you have got in your body?" That kind of knowledge is not knowledge. But the Supreme, Bhāgavata says that He knows everything directly and indirectly. I know I am eating, but I do not know how my eating process is helping my circulation of blood, how it is being transformed, how it is working, how it going through the veins. I do not know anything. But God must be He who knows everything, every corner of His creation what is going on He must know. Therefore the Bhāgavata explains, that Supreme Truth, from whom everything is emanated, He must be supremely cognizant. Abhijñaḥ. Abhijñaḥ means cognizant.
That, you may question, "Then if He is so powerful, wise and cognizant, He must have learned it from similar..." No. We say that if he learns knowledge from somebody else, then he is not God. Svarāṭ. Automatically. He's self-independent. This is jñāna-yoga. The study what is the nature by just analyze what should be the nature of the supreme from whom everything is emanating. That is explained in the Śrīmad-Bhāgavatam.