The average man, who does not know what to do with his life, wants another one which will last forever.
— Anatole France, The Revolt of the Angels
You wasted life, why wouldn’t you waste the afterlife?
— Modest Mouse
So you want this lovely consciousness of yours to last forever? Is that not immodest? Are you not mindful of all the other things which would then be obliged to endure you to all eternity, as they have endured you up to now with a more than Christian patience? Or do you think to inspire them with an everlasting sense of pleasure at your existence? A single immortal man on earth would be enough to drive everything else on earth to a universal rage for death and suicide out of satiety with him! And you earth-dwellers, with your petty conception of a couple of thousand little minutes, want to burden eternal existence with yourselves everlastingly! Could anything be more importunate! Finally, let us be indulgent with a being of a mere seventy years! He has not been able to imagine the everlasting boredom he himself would experience – he has not had enough time to do so!
— Nietzsche, Daybreak
A disclaimer: I’m no medical researcher. I’m a fiction writer. While I do routinely stick my nose into a host of nonfiction subjects that are none of a fantasist’s business, I’m still in no position to analyze the prospects of success for cryonics, stem-cell therapy, nanotechnology, telomere extension, transhumanism (which foresees the uploading of consciousness to more-durable synthetic bodies or computers), the eradication of senescent cells, or the life-sustaining effects of living a hundred days underwater. But I’m as qualified as anyone to wonder: Why is the clichéd search for a fountain of youth accelerating, with no apparent sense of embarrassment? Is the ambition to hang about indefinitely healthy or warped? What might be the up- and downsides of living for hundreds if not thousands of years? And what could a greatly protracted or veritably infinite life be like?
…With only about 80 years to play with, plenty of people already have difficulty coming to grips with what they’re here for and what they want to accomplish. Many a mortal already finds life meaningless. In the face of an indefinite ellipsis, of being and being and being, the burden of finding purpose and meaning could grow unbearable. Why, today’s longevity crusaders derive their own senses of usefulness and direction by fixating on the defeat of death. Were they to succeed — job done, no one dies — what would they do with themselves? They’d need a whole new quest.
— Lionel Shriver, “The Modern Quest for Immortality“