There was a time only a generation or two ago if you made it to 65 you were expected to wind things down and more or less get ready to die. Not so any more. My mother is pushing 70, still works full time with no plans of quitting, exercises regularly, and she has not slowed down very much or seen an increase in her health problems. She looks about 50 something. Some factors are better health care, emphasis on exercise, less physical work, better nutrition, and better knowledge of diseases and their causes than previous generations had. In that graph you can see the countries where hard physical work is the norm is where lifespans were very short, but all the factors contribute.