The only ones I hear say that are those who, through poor life choices, can't afford to retire comfortably.....Mostly they are guys that had multiple marriages. Those of medium means can't build wealth exchanging families every 10-15 years.
About the only one I know that I think is on the level is a former classmate that became a Zoologist and works for the Smithsonian (National Zoo) research center in my AO. He said he will stay there (lives on site with his wife) till he dies or they run him off.
He said he mostly works with the big cats. LOL....I asked him if he was a "big cat wrangler" (a real .gov job there that was advertised some years ago) and he said no but he may as well be.