No you missed it. Unless you're a professional profiler for the FBI you're gullible, to a certain extent, to something, everyone is. Otherwise, Ponzi and Madoff couldn't have taken advantage of otherwise savvy investors.
You meet people, you try to read them, you take a leap of faith. Guilty as charged, I've concluded it's not my strongest point, but that hardly exonerates the perpetrators. Let's not blame the victims, shall we?