I may be from the bog but Im not turf
Means you’re from the bog but you’re not the biggest fool. You’re just a bit thick and think you’re the smartest.
'I may be from the bog but I’m not turf, I beat my cousin at chess.'
'I may be from the bog but I’m not turf, I can spell my name.'
'I may be from the bog but I’m not turf, I didn’t need help with that.'