That's a quote from Michael J. Fox discussing his outlook on Parkinson.

Probably not very. I think of people like Pat who struggles to get from her car to her desk. However, while her physical activities have been bound by her illnesses her mental outlook hasn't. That's why I admire her. So when I feel overwhelmed by my pain, I think about her. I can walk, drive, paint, clean, weld (badly), write, knit, cook, exercise and all the other things I do everday without a struggle. So, I don't think I'm sick. I just hurt sometimes.