Someone who seems "addicted to feeling smug" is likely seeking constant validation for a grandiose sense of self importance. The smugness is the emotional payof

Someone who seems "addicted to feeling smug" is likely seeking constant validation for a grandiose sense of self importance. The smugness is the emotional payoff. The fix. That temporarily works up their fragile self-esteem. This pattern of behavior is most closely associated with Narcissistic Personality Disorder in the DSM-5.