I think I've already met more than one person who said something like, "I don't wanna get old. That's why I smoke and practice other unhealthy activities, so that I die young :3"
Bloody fools. Instead of safeguarding themselves from the suffering of old age, they will most definitely prolong it. Instead of living in pain from, say, 70 to 75, they will live in pain from 40 to 60.
But I know how desperate they may feel. I too don't wanna get old. I sometimes look at the infirm elderly on the streets: such an abhorrent life. Unpleasant-to-look-at meatbags, they can barely see or hear, they can barely walk. They limp, stumble, fall, break their brittle bones. And still they push themselves back and forth, to the grocery, or the pharmacy, apparently having no one who'd do it for them. Can I become like that? It may become like that. It's unlikely that I will have descendants who will take care of me. It's unlikely that I will be rich enough to hire a caregiver, or live in a country that provides one.
It's unlikely that I will produce anything of value while having such a body. Hell, I struggle being productive even now. What a miserable state of existence it would be. Won't I just commit suicide? I try to imagine myself in that situation. It's difficult to be objective while not experiencing any of that. But I fear the answer may be no: I may still prefer an abhorrent life to death.
It's sad. Death can be sad, but the lack of death for the certain people can be just as sad. We can fix it.