Meet the Johnsons, a family of five recently profiled by The Washington Post. The Johnsons live in Culpepper, Va., and bring in $90,000 per year -- a full 55% above the median household income for the town. Based on this alone, you might think mom and dad are prime candidates to retire early.

Then again, the family has to pay the bills. All three daughters have a computer in their room, the family shares a laptop and three iPads, satellite TV is available on three flat-screens throughout the house, and all family members except the youngest have a cellphone.

Their savings for college: $0. Their retirement savings: "meager."

When asked what more they'd need to feel financially secure, Mrs. Johnson says:

$150,000 a year. If we had an extra $60,000 a year, we'd have some breathing room. I'd like to have some extra things. Not just look at them and drool.

While I have no doubt that the Johnsons are genuinely good people, it's this type of mind-set that will stop anyone -- regardless of their income level -- from ever being satisfied with their financial situation.

If you want to retire early, it is more possible than ever
But let's give this family some credit: They aren't wildly unusual. Believe it or not, we Americans have never been good at saving for retirement. All of those ideas about the "golden years" of the 1970s pensioners are largely myths.

In fact, retirement alone is a relatively new concept. Historically speaking, people have only recently begun to live long enough to leave the labor force with leisure time on their hands. And even in most of the world today, grandparents commonly live with their children and grandchildren -- so retirement savings didn't need to be so financially all-encompassing.

But the fact of the matter is that today, there are a lot of ways for average Americans to reach early retirement. The solution is both incredibly simple and incredibly challenging. It is the necessity to ditch the middle-class mind-set.

While there's no definitive book on what the "middle class mind-set" is, in the slideshow below, I'll take some oft-cited rules of thumb and show how ignoring them can be hugely beneficial to your financial independence.