People segment themselves. I was going to say that they segment their lives, but this is of course an ephemeral or conceptual division that proceeds directly from segmentation across time of the self. That is to say that someone is one person (for example, a worker) one moment and another person (for example, a friend) the next moment, and this sort of thing leads to temporal segmentation, i.e. working one moment without thought of friendship and talking congenially with a friend the next without thought of work.
This segmentation of the self is not absolute, of course, but it is something that most people do to a greater or lesser degree. (In some people the facility is very well developed indeed.) I on the other hand cannot do it at all. I am always all of the things I am, simultaneously, all the time. I am unable to separate the friend from the co-worker or the personal from the public. This skill is, however, tremendously important in our time, and my inability to appropriate and to deploy it is often a serious liability.