I realize that his confidence is simply an external display of a rich interior life—congruency between his internal and external worlds. Arrogance, on the other hand, is the opposite of confidence: a veneer of composure, incongruence at its zenith. This is why a confident man is able to coalesce with any group, anywhere; an arrogant man, nowhere at all.
Confidence holds up under scrutiny, whereas arrogance fractures with the slightest crack. And, as human beings, we all have cracks. Sooner or later, a spotlight is shone and the arrogant man’s pomposity is exposed, seeping through the veneer, while the confident man just admires the beauty of his flaws.
(Da The Minimalists)