I've smoked for some odd 30 years. Been very healthy and active over my life.
I LOVE to smoke, but when I laid down to sleep at night lately I hear wheezing sounds come from my lungs. I could cough and clear the obstruction but I'm like.... WTF.
So I quit again, my lungs cleared almost immediately. Still coughing up crap but less and less everyday.
All I have to do is not put a cig to my lips and inhale. So far so goo w/ living w/ a smoker.