I've been smoking since 1974. Haven't been sick since the last time I seriously tried to quit smoking!:-) And that was just before I left Wisconsin back in 1983. Couldn't leave the house for 3 days. Haven't missed a day of work since, except to go skiing!
The only thing that messes with me know is when we have a couple weeks of 40 degree temperatures, then a Santa Ana blows in and it warms up to 90 degrees in a few hours. Get a runny nose for a few days.=20
Matt