A condition in which a person has an unexpected, at least to others, zero or very near zero response to a situation in which other, lesser people, would have felt something of a substantial nature.
I'm at the taqueria, got a super burrito, my girl got a quesadilla and 2 super tacos. I gotta go back at least once more though to get another super burrito, I ate the super burrito and one of her super tacos and felt nothing.