And because the differences we notice and care about are the ones that provide satisfying explanations of prominent experiences, such as loneliness or frustration with others' behavior. A quality of the self that works 'behind the scenes', the kind that only comes up when we talk about the theory of the mind on a fairly high level, will not usually seem like a candidate for such explanations. For example, I've known I was smarter than average since childhood, but it took me until college to notice that I was color blind. And color blindness is fairly concrete- like, the relationship between categories and central examples is almost certainly different in my head than in the average guy on the street, but there's no real way of knowing.

(Or perhaps I'm falling prey to the typical mind fallacy, natch.)