O supreme Purusha (dweller in the body), You alone know Yourself by dint of Yourself. You are the source of all beings, the Lord of all creation, God of gods, Ruler of the entire world.
If both gods and demons are unable to know Krishna’s greatness, there is only one left – Krishna himself. Even otherwise, one first comes to acquire greatness and then alone his greatness becomes express in his life.
Thus any quality is first known to its possessor. Thereafter others begin to observe it. Here, the greatness is of the invisible Self. Everyone is the Self, but none generally probes to understand it. Krishna proves an exception, in that as a charioteer he exposes it to the master of his chariot. Where to find such a one!
Yama discloses to Nachiketas in Kathopanishad (1.2.7): “Many do not get an opportunity to hear about the Self; those few who do hear, are unable to know it well. Rarely wonderful is the true exposer; exceedingly fortunate is the one to hear it from such a one. Still rarer is the one who, well instructed, is able to know the Self in full!”