We're all morons outside of some very narrow areas of expertise. By most criteria James Mattis would be considered a smart guy: he earned a Master's degree, commanded troops effectively in combat, and served as Secretary of Defense. And yet he fell for the Theranos fraud. You have to know your limitations, and too many people think that because they're good at one thing they must be geniuses who are good at everything. Engineers are especially prone to this delusion.