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Let us assume you have 20 years to get the figure from scratch, $400,000 / (20x12) = $1666.66 pure savings a month, now I won't know if that number is a coincidence, but for a normal joe it is simply a piggy bank too far to reach. At any rate by the time you are really 55 (assuming 20++ years from now) one can really doubt if a million dollars will be enough for you to retire in style.
In short, 95% of the world's population can't really afford to retire.