Methinks perhaps Vaan suffered a Traumatic Brain Injury which resulted in significant damage to the left lobe- rendering him incapable of pessimism, sadness, and the negative.

Or it could be he suffers PTSD and the Vaan we see is the biproduct of severe survival coping mechanisms.

Or maybe, just maybe, Vaan is the consequence of end-of-budget production times over-worked and under-paid developers. Squared.

;)

Stellar article my friend, I like your style.