As stated in an earlier post: "You factor in the younger wife who will keep working a bit when your retire."
As a widower approaching 60 with two college age kids, I envy such a retirement plan. Fortunately, my late wife, who did not work in the traditional sense, but did manage the household and the family finances, set us up well with investments. As a "traditional" family, I brought home the bacon and the wife fried it up in the pan or through her investing skills, turned it back into the whole hog. By such a division of labor, we also avoided childcare costs and she was able to volunteer with and be a part of the kids' activities, especially when I was away from home on military service.
A common takeaway from this thread is that it is easier to go through life with a partner.
To those who question amassing a large retirement fund, having the funds available is a means of self-insurance and self-reliance. Both of my parents were Depression Era kids and not too far removed from the farm, so they had and passed on a sense of frugality and true conservation (ever see a clothespin bag made from a recycled pants pocket?).
Long-term care is something that has not been mentioned much on this thread. The government (i.e. other people you do not know) should not be responsible for you as you age, and it's very likely that many will age in a debilitated state. My father lived for a decade with severe dementia, so I need to plan for the same.
If the government allows me, and this statement made in a country founded on limiting the power of government, I would like to exert my privilege of family, study, hard work, service, and clean living by passing on a legacy to my children. It's my money, not the government's despite what China Joe thinks. As time goes by and it becomes apparent that I may not need all of what I have saved, I would like to pass some of it on to others based on my own terms. I am no Andrew Carnegie, so I won't be funding libraries across the country, but I would like to establish scholarship funds through some of my favorite "special interest" organizations (what organization isn't devoted to a special interest?) or fund organizations that hold the same values that I do.
I'd like to step away from my corporate job between age 60 and 65, but not "retire", but rather transfer by knowledge and skills to a non-profit position supporting a purpose/mission consistent with my values.