Lloyd Blankfein went from being a poor kid on a Brooklyn housing project to a Harvard graduate, a corporate tax lawyer, then the CEO of Goldman Sachs.His titanic change in circumstances required a major shift in mindset, Blankfein explained in “Streetwise,” his memoir published this spring.He wrote that “growing up in public housing, in a family that was just getting by, and attending public schools that were failing, left its mark on me.”When counting every…