Bhagavad Gita, Chapter 7, Verse 3

One, perchance, in thousands of men, strives for perfection; and one, perchance, among the blessed ones, striving thus, knows Me in reality.

Even genuine effort and real achievement don't automatically guarantee the deepest understanding.

This is a sobering, honest admission. Trying hard is rare enough on its own, and even among those who succeed at that, truly knowing what's being described here is rarer still, real depth isn't a given just because someone's put in the work.