His father worked well into his late 60s before he retired. They both continued to work past normal retirement age, not because they needed the money, but because work is virtuous.
Work keeps one's mind active and provides a sense of purpose.
I am speaking of the infamous Social Security earnings test. It imposes punitive tax rates on seniors, thus driving them out of the labor force altogether, or reducing their hours worked. This is blatant age discrimination by our government and should be ended now. It is also incredibly economically muddle-headed federal policy. We all know our work force is aging.