Well first off on the average age. Remember, average life expectancy means starting at birth. People who die at age 1, tend to deflect the average down considerably more than people who die at age 80. For the life expectancy to be 81, a large proportion of the people have to live beyond 81.

Being fit and active can prolong one's active life considerably. But being only as old as you feel is balderdash. Most people are old in their late 80's or early 90's.