Ask anyone at a milonga, "Why do you dance?" and you will probably hear, "What do you mean, why? Because I like to dance!" Of course, it's unlikely that we would spend so much free time on the dance floor without gratification. But gratification is a result; the underlying motivation is deeper. Motivation in this case may be attributed to one of two diametrically opposed objectives: self-expression and self-validation. When one of these objectives is met, we're gratified.
Self-validation is a fleeting satisfaction of a desire for a label or valuation, which usually comes from the outside, from someone else. Even when I label myself, it's pure self-validation.
Self-expression is a state, in which no valuations are necessary. Self-expression is when my knowing of who I am comes from within, and is expressed in my thoughts, words and actions.