What keeps you going?

I have learned and continue to learn different coping techniques to deal with my chronic pain, and much of the time I feel like I am able to cope. But then there's the bad days, the really bad days, the days that just make me want to quit and give up on life totally.

How do you keep yourself going when it feels like the reasons to continue are totally outweighed by your pain? What makes continuing a pain filled existence worth it? Even with all my coping techniques, I often feel like I can't justify reasons to keep on with life when the pain is at its latest peak.