AtD translation: worn insolence

[Mike Jing]

P330.21-28   “Sometimes the real world, the substantial world of affairs,
possessing greater inertia, takes a while to catch up,” Kit carefully
pretended to instruct him. “The Maxwell Field Equations, for example—it was
twenty years till Hertz discovered real electromagnetic waves, traveling at
the speed of light, just as Maxwell had worked it out on paper.”
       “Twenty years,” smiled Scarsdale Vibe, with the worn insolence of
someone expecting to live forever. “I’m not sure I have that long.”
       “All sincerely trust that you do,” replied Kit.

What exactly does the word "worn" mean here?