No man is a good doctor who has never been sick himself.

The proverb claims that competence in caring for others depends on intimate knowledge of vulnerability. “Sick himself” functions less as a literal credential than as a metaphor for having faced pain, limitation, or crisis. A doctor who has suffered is presumed to treat patients with greater humility, patience, and realism, because he understands illness from the inside rather than as an abstract case. More broadly, the saying endorses experiential wisdom: those who guide, heal, or advise are most trustworthy when they have been tested by the very conditions they address.