At first I thought it was to teach me a lesson about hard work, which seemed foolish, as hard work was already my life, or humility, of which I probably did need a dose.
A few years later, he told me his true reason. He said,
"If you want to know who a person truly is, don't watch how he treats his friends or his boss.
Watch how he treats his janitors, his handymen, his surveyors, his receptionists, or his waitresses.
The measure of a man is not how he treats his supposed equals. It is how he treats the least fortunate among us."
Morality is not contingent upon income.