Ulysses - James Joyce

I feel a bit of a philistine giving Ulysses two stars, but if I'm honest, I didn't enjoy it that much. Reading it was too much of a chore. I know it's supposed to be the greatest thing to happen to literature since the invention of the novel. But it's just way too obscure, and way too dense, and way too boring.
It's about a day in the lives of two 1904 Dubliners, Stephen Dedalus, aspiring poet and student at Trinity College, and Leopold Bloom, adulterer and anti-Home Rule-er. And that's it. Just people walking around Dublin thinking about things. For 732 pages. Each chapter (or "episode"), corresponding to a different episode in Homer's The Odyssey, is written in a different way: one in stream-of-consciousness, one imitating all the different styles of English literature in chronological order (that one's the worst), one even written as a play. Yes, you read that right. With stage directions and everything.
It's got me thinking what actually constitutes a work of literature. Is good literature always "difficult"? Is it about telling a good story? Is it about elegant writing? Are you even supposed to enjoy good literature? Because I certainly didn't enjoy Ulysses. What is it about, Joyce? Any clues?
No.