Expressing yourself amounts to telling a story about your feelings, both to your audience and to yourself. The function of this act is to rationalize the imperatives our bodies place on us into a coherent and predictively useful model of our behavior, again both for our own benefit and for that of the social machinery in which we participate. This is how personality grows, or is grown, depending on whether you're the student or the parent.
There is a distinction, though, between what is accomplished for an audience and what is accomplished for oneself. The audience is your social machine, remember, and so its judgment amounts to how well you fit into its group dynamic. Self-judgment has different foundations, however, for the system of capacities and drives that disposes us so readily to immerse ourselves in society also, quite accidentally I imagine, enables us to view ourselves hypothetically.
A self-hypothesis is distinct from a personality in that a self-hypothesis is demonstrably not presently the case, like a physical ability, while a personality is composed of models independent of natural reality and so unconfirmable, like attitudes or prejudices.
This capacity for self-hypothesis works almost like a mechanism of revision or growth for society, for as we imagine ourselves rich or popular or adequately fed, we necessarily imagine a world in which this would be so, and we yearn. This yearning, I believe, is responsible for the lion's share of human-directed change to our society, whether intentionally through social justice movements or unintentionally through personal ambition.
