They seldom smile or they laugh too long, too loud. They are at the center of activity, effectively leading to accomplish goals or they are quiet at the perimeter, contributing little. Pretty, handsome, well-groomed, simple, plain; age, gender, socioeconomic standing--nothing appears to be a common factor. The sense of non-entity, loneliness, namelessness can happen to anyone, at any time, and for any length of time. Everyone is vulnerable. It's...