The difference between genius and stupidity is that genius has its limits.

Sometimes people really don’t have our best interests in mind.

Stupidity is better kept a secret than displayed

Something reduces the speed of the world and that something is stupidity! Stupidity is a boring friction!

It's the wrong way. She's farther away from the door now. It occurs to me that some people only have book smarts.

Obviously this person's a hazard. Stupid people are dangerous.