I am in a position to be intimately familiar with illness. I will say that health is a spectrum and the mind is incredibly resilient. You will surprise yourself as you inevitably age how much your mind will adapt to always hurting. There is more to life than body discomfort. This patient sounds like he has his faculties and is making an informed decision to continue living, because his life is worth the discomfort he is going through. I am reminded of a line along the lines of every day you experience, no matter how terrible, is very likely a day that someone else yesterday would have desperately wanted.