John F. Kennedy in New Yorker

On Principles & Values: JFKs's Addison disease kept secret for decades

Yet it is impossible to conceal the sheer physical strain of the Presidency. The absence of peers and friends takes the greatest toll. Kennedy, who liked to compare his critics to hecklers at a bullfight, quoted a poem by the matador Domingo Ortega: "Only one is there who knows / And he's the man who fights the bull."