WHY WE CAN NEVER BECOME LIKE KRISHNA IN MEMORY?

Because, We do not know what we did nin our previous births.  But, Krishna knows the karma of all the billions of persons.

SRILA PRABHUPADA SAYS:

There are various classes of men in the world who speak of God in different ways, but according to Vedic literatures and according to the great acaryas, the authorized persons versed in the knowledge of God, in all ages, like acaryas Sankara, Ramanuja, Madhva, Visnusvami, Lord Caitanya and all their followers by disciplic succession, all unanimously agree that Krsna is the Supreme Personality of Godhead. 

As far as we, the followers of Vedic civilization, are concerned, we accept the Vedic history of the whole universe, which consists of different planetary systems called Svargalokas, or the higher planetary system,  Martyalokas, or the intermediary planetary system, and Patalalokas, or the lower planetary system. 

The modern historians of this earth cannot supply historical evidences of events that occurred before Homo sapiens had not appeared on this planet because evolution had not reached that

point. But the Vedic histories, the puranas and Mahabharata, relate human histories which extend millions and billions of years into the past. 

For example, from these literatures we are given the histories of  Krsna's appearances and disappearances millions and billions of years ago. 

In the Fourth Chapter of the Bhagavad-gita Krsna tells Arjuna that both He and Arjuna had had many births before, but, He (Krsna) could remember all of them and Arjuna could not. This illustrates the difference between the knowledge of Krsna and that of Arjuna. 

Arjuna might have been a very great warrior, a well-cultured member of the Kuru dynasty, but after all, he was an ordinary human being, whereas Krsna, the Supreme Personality of Godhead, is the possessor of unlimited knowledge. 

As He possesses unlimited knowledge, Krsna has Boundless memory!