The human brain is a wonderful thing. It starts working the moment you are born, and never stops until you stand up to speak in public.

The joke hinges on an ironic reversal: the brain is praised as constantly active, then immediately undercut by the claim that it “stops” at the very moment one needs it most—when speaking publicly. Jessel compresses a common experience (blanking out, losing one’s train of thought, sudden self-consciousness) into a neat comic paradox. Beyond humor, the line points to the mismatch between private competence and public performance: anxiety can temporarily disrupt memory, fluency, and judgment. Its enduring appeal comes from how it normalizes that fear, letting audiences laugh at a vulnerability many share.