As a registered geriatrician I keep tabs on the tools of my trade particularly its language. In this regard I draw attention to the two phrases "life expectancy" and "life span." In my reading in the domain of aging these two are often casually misused, leading to confused conclusions. They are often presumed to be interchangeable, which they are not. Life expectancy and lifespan should, could be synonymous. In the ideal world we would all live to our maximum of 120 years, but the real world reveals a very different scenario.
Let's look at dogs for example. The Guinness Book of Records reports that the oldest dog that was verified was a cattle dog who lived to be almost 30 (and herded almost to the end). My and your experience with dogs is far lower, maybe 12 if we're lucky.
For us humans the longest verified life was that of Madame Jean Calment of Arles, France. All agree that she lived to be 122+. Her doctors used to report on her condition to us at medical meetings when she was still alive. We paid attention. Her life thereby establishes the human life span as 120, to make it simple. This number 120 has not changed since our species began, and is not likely to anytime soon -- 120 is the human lifespan.
Only one person so far has reached this potential. Many others are crowding upwards. The International Registry of Supercentenarians in Los Angeles currently includes 77 persons over 110 in the world, two are 116. What about the rest of us? I maintain as many others do as well that most of us die too soon. (1) We live too short. Our life expectancy falls far short of our lifespan. Why? 10 Nobel prizes await the answer to this question. My answer is that we die too soon mostly because of health illiteracy. We die because we are not heeding important new information about how to stay healthy. Our lifestyles suck. We pay a heavy price for this dereliction.
My take on all of this is a 100 healthy years. This is my personal life expectancy. I'm planning to do this and working at being financially able so. After 100, I plan to die broke.
Bortz, Walter M. "We Live too Short and Die Too Long. Bantam NY, 1991.