Rare is the person who truly perceives the soul. Rarer still is the one who can speak of it accurately. And even among those who hear about it from a realized teacher, most walk away without fully grasping what they heard. Krishna is acknowledging, with a kind of quiet awe, that the soul remains a mystery even to those who approach it sincerely.
This is not a discouraging statement — it is an honest one. Some truths are so vast that encountering them feels like standing at the edge of an ocean at night. You sense the enormity, you hear the waves, but you cannot see where it ends. The soul is that kind of truth. Each person touches a different edge of it — one through direct experience, another through teaching, another through listening — and still it remains larger than all of them.
There is humility woven into this shloka. Even Krishna, in the act of teaching, pauses to note that the subject is beyond easy comprehension. The soul is not a concept to be mastered in one sitting. It is a lifelong unfolding.