In my case, Raggy, it was simple absentmindedness: I clean forgot I was supposed to retire, until Herself towed me away for the Caribbean cruise that was supposed to celebrate my retirement. It did pad out my pension a tad, which will be selflessly passed on to the next generation once I date-expire completely and/or save them paying for a rest home for me in the meantime.

More generally, older workers aren't selfish, just more expensive.