My reasons for living:
- My Wife
- So many books I'd love to read, records I'd love to listen to, etc...
- Family (at least, the ones I know really care about me)
- George Herbert's advice: "Living well is the best revenge"
- I still have something to contribute towards making the world better, I just haven't figured out what yet.

PS: Your post also reminded me of an old Modern Lovers song called Dignified and Old -- "But I can see through this bitterness and sadness, And so I won't die, Someday I think I'll be dignified and old"