My father-in-law is 84 years old. “Pop” as we call him, never misses his daily fast-paced five mile walk. He’s tech savvy and knows more about current events than most people half his age. He still mows his lawn in 90 degree Georgia weather and never meets a stranger.
Some fifty year olds are young, some are old.
Some sixty year olds are young, some are old.
You get the idea.
What makes the difference? Young is a state of mind.