Ok massive generalisation but I see a lot of people talking about how they're 40 or so and have 20 + years before they retire.
As a society, we're more sicker, more stressed and more busier than ever. These things would shorten your life expectancy. I can't imagine working till I'm nearly 70- I'm not even 40 and I'm already knackered! I think I'll be dead before I reach retirement age. I know so many people who have died before 60. They never got to retire and enjoy a work free life.
I know people can retire earlier but not many people have a decent pension that i know of and are forced to work till they're nearly 70 or till ill health.