As he watched Joe stand, blazing, on the fire escape, Sammy felt an ache in his chest that turned out to be, as so often occurs when memory and desire conjoin with a transient effect of weather, the pang of creation. The desire he felt, watching Joe, was unquestionably physical, but in the sense that Sammy wanted to inhabit the body of his cousin, not possess it. It was, in part, a longing--common enough among the inventors of heroes--to be someone else; to be more than the result of two hundred regimens and scenarios and self-improvement campaigns that always ran afoul of his perennial inability to locate an actual self to be improved. Joe Kavalier had an air of competence, of faith in his own abilities, that Sammy, by means of constant effort over the whole of his life, had finally learned only how to fake.
That's to get you to go read it. Discuss on November 27!