This is Yamraj (the god of death) speaking to the young boy Nachiketa. Nachiketa had asked for the ultimate gift: knowledge of what lies beyond death. Yamraj first tries to dissuade him with riches and pleasures — but Nachiketa persists. Then Yamraj reveals this deep truth.
The Atman — the innermost Self — cannot be grasped through argument, brilliance, or scriptural learning alone. It reveals itself only to the one who truly yearns for it, who turns all of one's being toward it.
This is not anti-intellectual — it is saying that the intellect is a tool, not the destination. The final step is a kind of surrender, a deep inner yearning that draws grace.