explain this to me, please.

I'm sure I'll have more to say about the Oscar race at some point, despite having seen very few of the contenders. But I have a question:

What is Before Sunset adapted from?

Did Ethan Hawke write another bad poem? (Because bad poems make great movies; it's a truism.)

I'm at a loss for an easy answer here (and the intarfriend ain't helping). What am I missing?

Also: see Uncle Grambo's profoundly wonderful reaction to Paul Giamatti's snub.