Foolish People
Many people misunderstand that the universal form becomes concentrated to take the form of Krishna. They are described as foolish by the Lord.
Lecture on "Understanding Krishna through Bhagavad Gita" – Salem – 8th Nov'06
A Fool
Its difficalt to say who is a bigger fool, one who things himself to be happy in this material world or one who thinks he will become happy by his plans in the future.
Fools and Transcendentalists
There are only two categories of happy people in the material world: fools and transcendentalists. Fools are so oblivious that they manage to convince themselves that they are happy in this material prison. Transcendentalists are happy because they can see above the material dualities and know that their parole is at hand. Everyone else is essentially miserable. This is because calamity in the material world cannot be avoided, just as water cannot be avoided in the ocean.
Reference: Spiritual Warrior III: Solace for the Heart in Difficult Times, Chapter 6 – A Spiritual Warrior's View of the World