Foolishness is all a question of opinion and perspective. What seems silly to one set of people, may well seem quite OK with another group.
The fact is intelligence or what is normal or mad, is an arbitrary measure. Who is to say what is foolish or which person is a fool?
Sanity, normality, intelligence, all these things that societies use to ensure compliance and mass conformity are just a question of which side of the fence you sit on.
The fool is perhaps the person who never questions this and accepts the rules of what defines the fool.
Maybe try foolish sometimes and see what the world looks like from the other end of the telescope.