Kṛṣṇa does not change His constitutional position, not even when He appears in this material world. Ordinary living entities have their constitutional spiritual positions covered. They appear in different bodies, and under the different bodily concepts of life they act. But Kṛṣṇa does not change His body. He appears in His own body and is therefore not affected by the modes of material nature. In the First Canto, 11th Chapter, 24th verse, of Śrīmad-Bhāgavatam it is stated that the special prerogative of the supreme controller is that He is not at all affected by the modes of nature. The practical example of this is that devotees who are under the protection of the Lord are also not affected by material nature. To overcome the influence of material nature is very difficult, but the devotees or the saintly persons who are under the protection of the Lord are not affected. So what need is there to speak of the Lord Himself? To be more clear, although the Lord sometimes appears in this material world, He has nothing to do with the modes of material nature, and He acts with full independence in His transcendental position. This is the special quality of the Lord.
Any person who can understand the feelings of all persons and incidents in all places at all times is called all-cognizant.
A nice example of the all-cognizant quality of the Lord is described in Śrīmad-Bhāgavatam, First Canto, 15th Chapter, 11th verse, in connection with Durvāsā Muni's visit to the house of the Pāṇḍavas in the forest. Following a calculated plan, Duryodhana sent Durvāsā Muni and his ten thousand disciples to be guests of the Pāṇḍavas in the forest. Duryodhana arranged for Durvāsā and his men to reach the place of the Pāṇḍavas just when the Pāṇḍavas' lunchtime was ended, so that the Pāṇḍavas would be caught without sufficient means to feed such a large number of guests. Knowing Duryodhana's plan, Kṛṣṇa came to the Pāṇḍavas and asked their wife Draupadī if there were any remnants of food which she could offer to Him. Draupadī offered Him a container in which there was only a little fragment of some vegetable preparation, and Kṛṣṇa at once ate it. At that moment all of the sages accompanying Durvāsā were taking bath in the river, and when Kṛṣṇa felt satisfaction from eating Draupadī's offering, they also felt satisfaction, and their hunger was gone. Because Durvāsā and his men were unable to eat anything more, they went away without coming into the house of the Pāṇḍavas. In this way the Pāṇḍavas were saved from the wrath of Durvāsā. Duryodhana had sent them because he knew that the Pāṇḍavas would not be able to receive such a large number, and thus Durvāsā would become angry, and the Pāṇḍavas would be cursed. But Kṛṣṇa saved them from this calamity by His trick and by His all-cognizant quality.
Kṛṣṇa is always remembered, and His name is always chanted by millions of devotees, but the devotees never become saturated. Instead of becoming disinterested in thinking of Kṛṣṇa and in chanting His holy name, the devotees get newer and newer impetus to continue the process. Therefore Kṛṣṇa is ever-fresh. Not only Kṛṣṇa Himself, but also Kṛṣṇa's knowledge is ever-fresh. The Bhagavad-gītā, which was imparted 5,000 years ago, is still being read repeatedly by many, many men, and still new light is always being found in it. Therefore, Kṛṣṇa and His name, fame, qualities—and everything in relationship with Him—is ever-fresh.
All the queens at Dvārakā were goddesses of fortune. It is said in the Śrīmad-Bhāgavatam, First Canto, 11th Chapter, 29th verse, that the goddesses of fortune are very fickle and restless, so no one can consistently captivate them. Thus one's luck will always change sometime. Yet the goddesses of fortune could not leave Kṛṣṇa for even a moment when they were residing with Him at Dvārakā. This means that Kṛṣṇa's attraction is ever-fresh. Even the goddesses of fortune cannot leave His company.