to lose their identity and become cancerous. And geneticist Nir Barzilai spoke of genetic variants in long-lived humans and his belief that all aging… - David A. Sinclair

Youth → broken DNA → genome instability → disruption of DNA packaging and gene regulation (the epigenome) → loss of cell identity → cellular senescence → disease → death.

prompting the United States in 1935 to join about twenty other countries that had already instituted a social insurance program. Social Security made moral sense. It made mathematical sense, too. At that time, just over half of men who reached their 21st birthday would also reach their 65th, the year at which most could begin to collect a supplemental income. Those who reached age 65 could count on about thirteen more years of life.32 And there were a lot of younger workers paying into the system to support that short retirement; at that time only about 7 percent of Americans were over the age of 65. As the economy began to boom again in the wake of World War II, there were forty-one workers paying into the system for every beneficiary. Those are the numbers that supported the system when its first beneficiary, a legal secretary from Vermont named Ida May Fuller, began collecting her checks. Fuller had worked for three years under Social Security and paid $24.75 into the system. She lived to the age of 100 and by the time of her death in 1975 had collected $22,888.92. At that point, the poverty rate among seniors had fallen to 15 percent, and it has continued to fall ever since, owing largely to social insurance.33 Now about three-quarters of Americans who reach the age of 21 also see 65. And changes to the laws that govern the US social insurance safety net have prompted many to retire — and begin collecting — earlier than that. New benefits have been added over the years. Of course, people are living longer, too; individuals who make it to the age of 65 can count on about twenty more years of life.34 And as just about every social insurance doomsdayer can tell you, the ratio of workers to beneficiaries is an unsustainable three to one.

And that's the world's biggest problem: the future is seen as someone else's concern.