He's an exceptional guy. He also knows this. Likely he had a phase in his late teens where he decided humility was a worthwhile value and way of being to integrate into his personality. Then he lived being humble for a while and realized how many people take things at face value, and didn't see him for all the exceptional qualities he has, and others lost out by his not speaking up of the positive ways he can contribute. After this learning experience, he's been penduluming back and forth between being overly-humble (to the point where he can't exercise his exceptional skills to positively influence his community) to being a little snobby, slowly tightening the distance that he swings from the idealized centre.
Figuring out how to do things in conceptual reality is way easier than figuring out how to do things in practice (and that universal fact is multiplied for an Ni dom).