I have a friend of a family friend who earned several hundred thousand dollars a year as a specialist in an advanced field. He declared bankruptcy in 2009 and will probably need to work well into his 70s. I know another who never earned more than $50,000 a year but retired comfortably on his own terms.

The only substantive difference between the two is that one exploited debt to live beyond his means while the other avoided it and accepted a realistic standard of living. Income and wealth aren't as correlated as people think.