(that's what's happening in Europe with the age of retirement being raised left and right. I mean it's just in e.g. Greece but where I live it's gone up by 2 years because there's a slightly older generation that are now all retiring, and the system is based on growth - that is, a younger generation paying for the retirement of the older one - instead of on saving, which causes the system to collapse unless they make people work longer.
So retirees are always extracting some fraction of the productive output of current labor. This fraction can go up or down depending on the economic growth rate and expectation of standard of living of retirees.
Social Security in the US has lent ~$2.6-2.9 trillion from its trust fund to the US government; imagine if that had been spent on driving down the cost of caring for the elderly instead of frivolous wars and tax cuts. You can't save up for the future to pay for expenses you can't predict; you have to invest today's dollars in getting ahead of the curve, to drastically drive down the cost of future predicted services you'll need to provide.
TL;DR Invest resources today to ensure a steep cost decline curve for existing in the future.
(well, ignoring the figurative worms, who were not in this study)
It seemed on point for this post: http://www.mrmoneymustache.com/2012/01/13/the-shockingly-sim...
If so you should probably update your comment to say "invest" instead of "save," which sounds nitpicky but the difference is huge.