And those points "ignore" income mobility because it mostly comes from transitioning from being a worker to being a entrepreneur of sorts. You don't generally work your whole life as a welder, for example, or a woodworker, and retire with $1M in the savings account (perhaps if you work as a surgeon, you do...)

Also, should we perhaps count the people who didn't manage to live to be over 65 in this percentage calculation of "20%"? That'll move that number down quite a bit, I am afraid.

> The rich people today were more often than not the poor and middle class of yesterday.

Well, poor people today are more often than not were the poor and middle class of yesterday too.