Some people live to 90-100, you should be allowed to vote when you're going to live for that much longer.

I semi-seriously believe that you should get more votes if you're younger, or a more heavily weighted vote, based on the average expected number of decades you have left to live. Like, e.g., an eighteen year-old ought to live for roughly another six decades, so their vote should be weighted to take that into account. And I say this as a thirty-[mumble] year-old! Eighteen year-olds should have more of a say than I do, because they're going to be affected by the decisions made now for much longer than I am.

I've been saying that each country should disenfranchise the elderly by the national average life expectancy minus the same number of years you have to be to register to vote. We accept that young people aren't fully developed and shouldn't be allowed to participate until they reach a minimum age. Time to do the same with people who are at higher risk of dementia and who won't have to live with the consequences of long-term changes.

I realize that this will unfairly disenfranchise able-minded people. They still shouldn't get a say in our long-term future.