People need to structure their self-understanding. We need to define a behavioral space within which are activities normally fall. Human players of the actual reality game are constantly seeking to find structure or to create it; our minds work more efficiently when reliable principles of organization reduce the range of what is possible. This is just as true of our self-understanding as it is of our understanding of the outside world.
In many cases, we try to define ourselves (and others) with the aid of labels: I am a programmer. I am a teacher. He is a concert pianist. These labels are a shorthand to describe a wide range of psychological and behavioral attributes. To say that I am a programmer is to say, for example, that I have a constructivist outlook and habit (rather than an analytical or interactive bias), that I think systematically, that I prefer to start from elementary building blocks.
At least that's what it means when I say this about myself. I find that a great amount of effort is required to convey the correct connotations of my categories to other people. That's one of the drawbacks of using labeled categories for self-understanding. The other drawback is that the labels are often more effective in drawing boundaries than in describing behavior; that is, it is easier for us to know what a programmer is not than about what a programmer is.
There is an alternative technique for self-understanding, which is to identify a exemplar or a model character: "I am like Thomas More", or perhaps "would like to emulate" him. One advantage of using an exemplar is that it is positive rather than negative; the exemplar's behavior is positive evidence about what I am (or, again, what I wish to become).
I do not want to be Thomas More -- he is dead and the proximate cause was a headsman's axe -- but I might want to be like him in some important ways. This implies another advantage to using exemplars, which is that it is less limiting than a labeled box. The exemplar defines a central tendency but neither excludes deviation from that ideal nor mandates the path by which to approach it.
Of course, deciding which of Thomas More's personal attributes are central and important in terms of my self-understanding is just as fuzzy and incommunicable as is the correct meaning of being a programmer. No solution is without its drawbacks, and that's what keeps this actual reality interesting.