Anyone can invent a security system that he himself cannot break. I've said this so often that Cory Doctorow has named it "Schneier's Law": When someone hands you a security system and says, "I believe this is secure," the first thing you have to ask is, "Who the hell are you?" Show me what you've broken to demonstrate that your assertion of the system's security means something.And that's the point I want to make. It's not that people believe they can create an unbreakable cipher; it's that people create a cipher that they themselves can't break, and then use that as evidence they've created an unbreakable cipher.
Seems to me like this observation could be made in a lot of contexts.
"I am not a <insert profession here>, but I'm smart and I think this, so this must be true."