Sometimes the simplest of phrases can have mountains of truth.  Mr. Micawber, a character from Charles Dickens novel David Copperfield, understood well the relationship between income and spending.  As many who had spent past their means in the years before the recent crisis can surely relate:

“Annual income, twenty pounds; annual expenditure, nineteen nineteen six; result, happiness.  Annual income twenty pounds, annual expenditure, twenty pounds ought and six; result, misery.”

-Charles Dickens, David Copperfield, pg 153