<i>but not THE secret to success.</i><p>That&#x27;s probably because there is no such thing as &quot;THE secret to success&quot;. In the real world, people succeed or fail based on a complicated mixture of many different parameters.  I doubt there is any one &quot;thing&quot; that we can actually prove is both necessary and sufficient for become &quot;successful&quot; (depending on how one defines &quot;successful&quot;).