It refers to a tendency all too common to place great emphasis on those details that we see as setting us apart from others. In other words, we ignore the overwhelming number of things we have in common with others, and focus in on the few differences, because these differences are what seem to define us as individuals. This reinforces the sense of self and keeps us feeling out-of-the-ordinary, but of course it’s also what keeps fueling conflicts with others over stupid little points of difference.