If there was one takeaway I was surpised by from &quot;The Millionaire Next Door&quot; it was, to paraphrase, high income professions like Law and Medicine tend to spend at very high rates, frequently invest poorly, and rarely accumulate a significant amount of wealth as a ratio to their income. The greatest wealth building households were two income, upper-middle class, with good, conservative savings habits. At the time of publication I think it was more valid than today, re: the change in distribution of wealth in the US over time.