That, as recognized during my final years in music school (now twenty years in the past, JFC), I'm lacking a basic, instinctual component of competence, a fundamental - potentially unlearnable? - tool, in my chosen craft. However, unlike in music school (couldn't sing, couldn't find a pitch in solfège; ignored structure and form which is probably why I'm such a junkie for it now, overcompensate much?), I haven't a clue what it is, only that it's there. Maybe.