We all accept that aging is a natural part of growing up. The human body is not built to last forever. In fact, we top out around 90 years of age. There are some incredible people who have surpassed this milestone, though these centenarians are few and rare. An Indonesian named Mbah Ghoto claimed he was born in December 31, 1870. If true, Ghoto's death on April 30, 2017 would make him the oldest person ever lived at 146 years old. But until the records can be verified, the world record for the oldest person belongs to a Jeanne Calment from France who lived 122 years and 164 days.
Biological aging is a complex process that scientists are still trying to figure out. There are many factors to a person's lifespan, including their genetics, their epigenetics, and their environment. What we often see as signs of aging, such as sagging skin, grey hair, are outward manifestations of the internal aging of cells. This involves mutations that we inherently acquire as we live and grow. And over time, the stress on the DNA and cells cause chain reactions that affect the turnover of cells. The older we get, cellular renewal seems to become less frequent and less efficient, making us feel and look old.
But while scientists are working out the exact mechanics of aging, it's important to remember that growing old is actually a privilege that not everyone is given.