For me, this novel is about sex. Stephen Dedalus is sexually frustrated. A perceived lack of success in the sexual realm seems to deeply affect Stephen's personality. His friend Davin is invited into bed by a woman and Stephen laments that no woman has invited him into her bed ("but him no woman's eyes had wooed"). Is this why Stephen wants to become an artist? I watched the movie ART SCHOOL CONFIDENTIAL and remembered the following dialog while reading A PORTRAIT:

"The history of art is largely about the implementation of masculinity.Part of some Darwinian imperative. Most artists become artists because they have no way to attract a mate. I hardly think I'm the first to point out that the vast preponderance of artists are, shall we say physiologically deficient in some way. "

Stephen wants to break free from religion, family, country and his friends. OK, so he does not want to leave Ireland for the sole purpose of getting laid :). He is a pretty well educated man and has thought deeply about art. But Stephen feels that his circumstances in Ireland are pulling him back or keeping him from achieving his full potential as a human being.