How do immortals deal with their long lifespans in your world?
I'm thinking that if you live long enough you may eventually become bored, or even worse, bitter and cynical. At least, I think, that's what would happen to a human if they suddenly turned out to be imortal.
Chances are that for races that are immortal by default (elves) the mindset will be a bit different, but it's still an interesting question. How does immortality affect the way you view the world around you and the way you live your life?