Let us say there is a Magical (or Alien, if you prefer, or Divine) Device that humans, acting as a group, can activate. If we do, average life expectancy becomes actual life expectancy. (Do not think about the details. It's a thought experiment!) So, if we do this in the United States, every infant born is guaranteed to live to (roughly - please let's not get hung up on the statistics, here) 78. But in return, you're giving up any years you might have lived beyond 78. And if you're older than 78 now - or if you love someone who is - well, it's goodbye. You are guaranteed to outlive anyone who is older than you are. But anyone who is younger than you are will outlive you, guaranteed. No one will die stupidly at 20 from cancer. (We're ignoring suicide, here, for the moment.) But no one will live to be hale and healthy at 90, either. If you're not in the United States, and you're curious about what your country's cut-off will be, you can find it here (as it happens, magic/alien/divine creations are perfectly happy to use Wikipedia as a source).
Would you do it?
And, okay, now let's say we can't do it just as a country. It has to be worldwide. So everyone's life expectancy becomes 65. Again, infant death becomes a thing of the past. Those people in Swaziland and Angola and Zambia and Lesotho - people whose life expectancy is, on average, at or below 40 years - suddenly get a whacking great additional chunk of life.
On the other hand, you, if you live in a first world country (or, indeed, almost anywhere outside of Africa - there are some Middle Eastern and Southeast Asian countries with expectancies below 65, and it looks like one country in Oceania, but mostly it's Africa), and you already made it this far (and aren't currently suffering any major illness or degenerative disease or anything), could probably have expected to live longer than 65. By a lot, most likely. You are giving up - on average, though no promises are made to you personally, of course - something like 15 years of life. And you're giving up a lot more people, too. As it happens, no one I love is over the age of 78 right now, but I do love people over the age of 65. You probably do, too. The fannish community skews young, but still, we'd lose people in the worldwide adjustment - I don't, as it happens, know any fans over 78, but I do know some over 65.
You get a vote, and let's just say you know in advance that your vote will be pivotal. How are you going to vote?
I am taking this poll!
If the Magic Device can be used on a country by country basis, do you want to use it in the country/ies where you are a citizen?
Turns out it's worldwide or nothing; do you want to use the Magic Device for everyone, so that we all live to 65 and no older?