It's interesting to think that of all the books that exist on money management these days, the concept of spending less than you earn is not a new idea. A simple yet crucial rule for financial success even 200 years ago.
"You find good businessmen who save all the old envelopes and scraps, and would not tear a new sheet of paper, if they could avoid it, for the world. This is all very well; they may in this way save five or ten dollars a year, but being so economical (only in note paper), they think they can afford to waste time; to have expensive parties, and to drive their carriages. This is an illustration of Dr. Franklin's 'saving at the spigot and wasting at the bung-hole;' 'penny wise and pound foolish.'...
"True economy consists in always making the income exceed the out-go. Wear the old clothes a little longer if necessary; dispense with the new pair of gloves; mend the old dress: live on plainer food if need be; so that, under all circumstances, unless some unforeseen accident occurs, there will be a margin in favor of the income. A penny here, and a dollar there, placed at interest, goes on accumulating, and in this way the desired result is attained. It requires some training, perhaps, to accomplish this economy, but when once used to it, you will find there is more satisfaction in rational saving than in irrational spending."
-P.T. Barnum 1810-1891