Justin Landis with an an interesting blog post he wrote in response to a Freakonomics podcast “Why Is ‘I Don’t Know’ So Hard to Say?”
[T]hose of us who live in the business world are certainly incentivized to focus on what we know over what we don’t know. And whether we’re talking about closing a deal with an important client or simply competing with peers for a limited number of positions in a given field, this holds true. By highlighting what we know and tactfully hiding what we don’t, we present the illusion of mastery, and this is thought to (and generally does) inspire confidence in our ability to execute. The incentive here is clear, and the results are pretty clear as well, at least in my experience. The unintended consequence is that while we’re all focusing on what we know and making sure others are aware of those things, there is still a lot that we don’t know. In some cases, we may not even really know what we don’t know. And this is the most dangerous place to be in.