A rich man is nothing but a poor man with money.
Fields is really saying something unsettling here: that wealth can't remake what's fundamental in a person. A stingy soul stays stingy whether he's counting pennies or millions—he's simply elevated his miserliness to a grander scale. The insight cuts against our assumption that money is transformative, that it erases our limitations; instead, Fields suggests it merely amplifies who we already are. You see this plainly in lottery winners who squander fortunes within years, or in newly wealthy people who remain as suspicious and small-minded as they were broke, just now with the means to act on those impulses at greater cost to themselves and others.