Smart has more to do with wisdom than intelligence.
Exactly, there are all sorts of types of wisdom and intelligence, some of which may even conflict:
- - Formal education
- - Spacial intelligence
- - Spiritual insight
- - Quick wits
- - Street smarts
- - Wily cunning
- - Charisma
Conan is wily, cunning, street smart, quick witted, survivalist, and charismatic; he can master a room of people with his force of personality, and knows exactly what he wants in terms of exercising his faculty of "will", where civilized folks have been often been over-civilized into sheep, but has virtually zero education (although he does make an effort to learn certain things, and in the cinematic version get taught formal fighting in the East). As we have increasingly seen of late, an education system is sometimes just indoctrination for a regime. Conan is a Nietzschean hero with an integrated personality, without the illusions of civilization.