I retired at 60. I first started looking seriously at retirement at age 53 (a little before joining this forum). Various calculators (including FIRECalc) and a Megacorp-provided financila advisor all said it was possible. But taken a closer look at our planned expenses, I decided I wanted a "comfortable" retirement living level, once that did not depend on me even having to work part time, or be required to take SS too early.
Given the amount of age discrimination occurring in the workplace, I did not assume that I could easily get a job. I also did not want to have to get a job requiring physical work - any good physical health I had left I wanted to spend on things for enjoyment, not for employment. So I kept working until my expected pension (fortunate to have one) grew to the required level, also building up a buffer of cash/investments assets well beyond what the calculators/planners said I needed.
While I was financially ready to go at 58, I decided to follow an "OMY Glide Plath" process for 2 years that I detailed here (
https://www.early-retirement.org/forums/f28/omy-glide-path-plans-81406.html), if you are interested. The result was me retiring in June 2018 at 60.
So far I am very happy with the results. I have a couple of friends who retired around the same time as me, but took on part time work. The coronavirus downturn is impacting their retirement. I still have very good health, and the market run up and fall down since I retired has helped reassure me that my plan is actually working. I have had offers for work from former colleagues, clients, and headhunters, but my head is just not into working full time or part time.
Of course, every person has their price... if someone came along with an offer of, say, no more than 8 hours a week, work from home, no physical work, paying $150 an hour or more, it would be tempting
.