“At times of success, a person’s basic test in life is whether he will haughtily attribute that success to his own efforts and abilities, or whether he will attribute it to Hashem.  Times of failure are likewise:  Will he blame himself or someone else for his failures, or attribute them to Hashem?  It’s easier for the poor man to understand that his poverty is the result of Divine will than it is for the rich man to understand that his riches are also the product of Divine will.  The rich and successful have a tendency to think that their own prowess is the source of their success.” ~ The Garden of Wisdom by R’ Shalom Arush as translated by R’ Lazer Brody