I don't suffer from chronic pain. In fact, I don't really know anyone who does. None the less, I found that after reading these articles I couldn't get them out of my head:
The second article reminds me a bit of the Four Burners Theory, which also tries to explain the limitations we face in life through a simple metaphor. Though I do think the Four Burners Theory is a bit more general.
While none of this is light reading, it's absolutely worth your time.