Phred Dvorak's "Theory & Practice" column in today's Wall Street Journal (subscription required) talks about the dangers of experience: "The more experience we have, the more overconfident we get," [says Kishore Sengupta, an associate professor at INSEAD who designs simulations that test for effectiveness in areas such as project management.] Alan Over, a managing consultant at U.K.-based PA Consulting Group who participated in Mr. Sengupta's simulation, says he now questions his assumptions more... "I try to force myself to be nervous," [Over] says. "Whenever I find myself falling back on what I did last time, or think I'm doing well, I try to unsettle myself." [My emphasis] I suspect Over's strategy of "forcing myself to be nervous" is an over-correction, but he's touching on an important dynamic. I've found that I'm more likely to make mistakes when I'm too comfortable, when I assume that I understand a situation because it feels familiar--in a word, when I'm settled.