So if you've decided you want to live until squid evolve to start swinging from trees, the first thing you should know is that while we accept aging as an unquestioned constant of the universe, it really isn't. The breakdown in our cells that causes us to get frail and wrinkly is a specific set of defects that science is just now starting to pin down. By all rights we shouldn't have to get old. After all, nature has plenty of examples of animals that suffer the whims of weather and disease, but if left alone in a germ- and disaster-free habitat would effectively live forever (including tortoises, certain jellyfish and some plants).
I WILL NEVER DIE.
With us, there is that enzyme, telomerase, which acts like the little plastic thingy on the end of your shoelaces for your DNA -- it keeps the ends of your DNA from unraveling. Unfortunately, every time your cells divide, some of this is lost, meaning you are breaking your body's ability to regenerate itself every time you grow or heal. Medical scientists are finding ways to either rejuvenate telomerase or prevent its loss in the first place. If they succeed, that could effectively halt or even reverse the aging process. At that point, youth could not only be wasted on the young, but also completely blown on the elderly, who would likely forget all their hard-earned wisdom with their reinstated endurance and sudden return of fully functioning boners.