I think the problem with people like this is that they are so stupid that they have no idea how stupid they are.

Too clever is dumb.

Let’s define dumb as being different from stupid. Dumb means you don’t know what you’re supposed to know. Stupid means you know it but make bad choices. […] Dumb used to be a by-product of lack of access, bad teachers, or poor parenting. Today, dumb is a choice, one that’s made by individuals who choose not to learn. If you don’t know what you need to know, that’s fixable. But first you have to want to fix it.

The most hopelessly stupid man is he who is not aware he is wise.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

Being stupid means avoiding thinking by jumping to conclusions.

Most fools think they are only ignorant.

But I am too stupid to be convinced by him.

Before I begin telling you what I think, I want to establish that I’m a “dumb shit” who doesn’t know much relative to what I need to know. Whatever success I’ve had in life has had more to do with my knowing how to deal with my not knowing than anything I know.

I believe that a scientist looking at nonscientific problems is just as dumb as the next guy.

The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence.

People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world.

The secret to my success, is that I'm just too dumb to know that I can't do it.

They're talking about things of which they don't have the slightest understanding, anyway. It's only because of their stupidity that they're able to be so sure of themselves.