Stupidity is intensified by things such as arrogance and confidence.

Most unintelligent or foolish people do not regard themselves as that; they regard themselves as not-that-intelligent or not-that-wise.

You can only manage to convince a person to admit to being wrong, not ignorant, arrogant, or stupid.

Getting older is not an intellectually demanding process.

Some people’s immaturity is intensified by their stupidity.

The kind of lies that someone tells us gives us an idea of how stupid, knowledgeable, intelligent, or ignorant they are … or they think we are.

The ability to utter wise words is not exclusive to the wise.

We sometimes unknowingly reveal that we are stupid by wondering aloud why, if they are really wise or intelligent, is someone not rich or famous.

99.99% of fools deny their foolishness. The rest underestimate it.