Someone posted a comment to the effect that vanity serves as a personal motivator for creativity. To that I will reply: if that is a sole motivator for an individual, that person either already has an established reputation which that person is attempting to maintain to retain a popular cachet (the vanity will only cheapen the accomplishment), or that the vanity is merely blinders that an individual has that hinders his ability to actually constructively and objectively evaluate that person's ability and talent.
Personal impetus (which are somewhat reflected in some of the interviews here in the Creative Process Ideas) may be:
A personal or group recognition that someone has something significant or useful to produce.
An attempt to expose or expand upon a perceived social or cultural fallacy which a person wishes to correct, or at least make relevant to a larger group.
A personal experience that incites a person into creative action.
A wish to make other people think: about themselves, their community, their culture, or other social or political structure - in order to initiate transformation in thought and/or action.
As an actor and director, I work very hard not to do 'trivial' pieces; when people come in to see a play or a film in which I participate, I want them to leave not quite the same person that arrived. I do other pieces in order to keep in practice, but I duck whenever possible, preferring to do tech and set work instead.
Art in any form should challenge people at some level so that they not only identify with something, but also re-evaluate in a very conscious way their values, way of life, or just become conscious of something in their own life that they may not previously have been aware.
I will add something that some may object doesn't belong in the Arts & Culture hierarchy: writing software is a form of art. While most people who use software may not see a piece of accounting software or a web browser as art, the appreciative audience here is other programmers. As a program designer or developer, one should strive for an elegance that, when reviewed by other programmers (especially in the Open Source community) causes them to say, 'holy frijoles, that is cool'. That, too, is art.