My father retired twice, for good at age 63. My mother retired at 62. Both worked civil service jobs and have great pensions. They are now in their mid-60s. They've talked about finding part-time work for a few years, but at this point I don't think it will ever happen. I think my dad wanted to hang on longer-- he really enjoyed his job, especially the social aspect of it-- but my mom convinced him to retire. Now, they sit home occupying themselves with watching television, emailing their adult children articles about depressing news and calling to talk about their health (they are in perfect health) and who is dying or died. I can't tell if they're enjoying their retirement or just going stir crazy.
They are well off and I so wish they'd get a second home in Florida but they find every reason on earth not to try something new. They'd rather sit in the same big house they've lived in and be frightened or amazed every year by the mostly expected weather patterns in the northeastern US. "I can't believe how hot it it is!" or, "Do you know we're supposed to get one ft of snow this weekend!"
I'm afraid they may very well spend the next 20-30 years this way.