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I don't believe that. Each person has their own expiry date, and it could change based on life choices, but it's not doom. Everyone gets the best basic unit (your body) that their parents genetic material can provide. All kinds of things can influence development, so there are lots of basic units out there that might be better or worse than yours. Some of the expiry dates might be exceptionally long or exceptionally short. Each of us faces the challenge of doing what we can with the basic unit we are given. The length of time we have is not really what matters. It's what we do with the time we have that counts. What's the point of living a quiet, sheltered life, alone and afraid, interacting with as few people as possible, not enjoying what life has to offer for 80+ years? Ending that kind of life earlier rather than later is not doom. What if your basic unit comes with a manufacturing defect? Would you want to suffer, in pain every day, to a ripe old age? On the flip side of that coin, what if you lived every minute like it was your last, laughing and loving every time you had the chance. Who is to say that 50 years of that would not be enough? Or 40? or 20? I think you can see where I am going with this. Death is not the enemy. It could just as easily be a merciful release as it is a threatening stalker. The real enemies are fear and waste. The length of time you have to live can't be measured in years survived, but more accurately by quality of life lived. If you leave the world better than you left it, remembered by someone you loved, that's all any of us can really ask.
Barring some incurable physical condition, or deprivation of the physical necessities of life, I don't think anyone is doomed to die prematurely. Whether or not life is worth living is a matter of subjective judgement, but there are many cases in which people feel life is still worth living despite what to others seem like insurmountable barriers to happiness.