This is a great topic, thanks for bringing it up.
From my perspective, attitude is everything. I remember the doctor 'whispering' to my Mom "he probably won't live to age 10". This was when I was 8.
It seemed like everytime I passed an 'expiration date', a new one was given.
I always figured, what the hell, if I ant gonna live long, I might as well enjoy the time I have. I didn't graduate from high school becaue I was too busy smoking pot with my 'friends' at the river, or wherever.
I started realizing I better make at least short term plans when I failed to die by age 18.
I never had many lung problems until my mid-later 30's. When they started, I went downhill fast! Before I knew it, I was on the transplant list.
Thank God that miracle came my way.
Now I just take every day as it comes. If I wake up, its a good day!
But enough of my worthless rambling. To sum it up, I truly believe attitude is probably 85% of the equation.
Best of luck to you, keep up the Good Fight!