It varies from person to person. For me I am still mostly a happy person despite being in pain. When I don't get enough sleep and with the combination of others, doctors, insurance company, supposed friends and those busy body family members who undermine what I am going through. Oh, it can't be that bad, you smile a lot. Or didn't you go to the doctors last week? See you got out of the house for that then you can for....here we can vent with out judgement.
Yes, this has robbed me of a lot. I don't dwell on that. I focus on my accomplishments and try a little more each time my body allows it. My mind does get sad....I feel jipped but I try to keep up the fight. And let it be known even down to the end....it didn't beat me, I just needed the extra rest.
So keep fighting my friend(s) and may to day be you pain less day for a good long while.