For Jim Roush, the act of returning to his childhood home in Indiana after failing to make it as a writer in New York is an act of utter desperation. He feels completely humiliated to have to live once again with his coddling mother, his indifferent father, and his suicidal brother who's even more of a head case than Jim is. (Indeed, Jim declares, "I mean, I'm a fuck-up, but you're a goddamn tragedy.")
Jim, played with wry brilliance by Casey Affleck (who's proving to be a master of understatement), is the quintessential failed artist who's bubbling with enough self-hate to fill a book but unable to channel any of it into anything resembling a successful creative life. Liv Tyler, who plays a down-to-earth nurse (and single mother), is a small glimmer of hope—a woman who doesn't see Jim as a bundle of past mistakes or a heap of unfulfilled dreams, but as a decent man just trying to make it day to day.
I know it doesn't sound like it from my description, but James C. Strouse and Steve Buscemi's Lonesome Jim (available on DVD) is also hilarious. One funny moment after another builds and builds, peaking with a ridiculous pep talk by Jim to a girls' basketball team—a half-hearted speech that is both a funny throwaway monologue as well as a weighty summation of Jim's fears, aspirations, and desire for self-forgiveness.
Off topic here: Casey Affleck, will you father my children?