Two things are infinite: the universe and human stupidity; and I'm not sure about the universe
A word to the wise ain't necessary, it's the stupid ones who need the advice
I am patient with stupidity but not with those who are proud of it.
"There is more stupidity than hydrogen in the universe, and it has a longer shelf life."
The dumbest people I know are those who know it all
Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity
In politics stupidity is not a handicap
Wise men talk because they have something to say; fools, because they have to say something
To succeed in the world it is not enough to be stupid, you must also be well-mannered