Here's an interesting statistic from one of the articles linked to the original post that I can attest to. Your last day at work may come as a surprise...
... typically half those retiring do not retire by choice. Instead, conditions such as disability, death of a relative, downsizing or a plant closing cause them to end their career earlier than planned.
http://insurancenewsnet.com/article.aspx?id=345573
They couldn't toss me out soon enough. We have a philosophy in my family. You take of yourself and then your kids they take care of themselves and their kids.