There is an older gentleman that works in my office, well beyond traditional retirement age (maybe mid-late 70s?). Several of us younger folk joke that he must either love it here or hate it at home because he comes in at 6 (there is no strict start time to our day, but the general rule is "before 9") and stays until 4 or 5 every day, with a ONE HOUR COMMUTE each way.
I was chatting with somebody about retirement the other day with him in the room and he volunteered some information about himself. Apparently he was involved in a small business startup when he was young that flopped about fifteen years in, less ten before he planned on cashing in and retiring, and took his entire life savings with it. Then he hired on at one of the big 3 auto makers and worked for them up until the year before he was set to begin receiving a (relatively hefty) pension when the recession hit, the company got bailed out by the government, and all pensions disappeared. With that company having a traditionally comfortable pension plan, he hadn't planned any retirement savings on his own. 35 years into his career he was left with almost zero savings (and if I had to guess, probably a mortgage and a car payment). He then joined our company where he has worked for 20-odd years, throwing everything he can into his 401k and index funds.
Kind of a sad story that he had such bad luck, but he had a lot of really good advice for us younger employees and served as a good example of what happens when you don't plan properly for retirement.