Speaking for myself, I'm (currently) entrenched solidly in the middle class. If you had told me 20 years ago what my salary would be today, I'd have replied, "Well, probably. I have a college degree, I'm a hard worker, etc etc etc".
However, if you had told me 20 years ago what my salary would be today AND that I'd be clipping coupons, skipping vacations and cutting every corner that I can find just to stay afloat..... I'd have said that you were crazy.
Oh gosh. Nailed it.