My dad smoked and I thought that I wanted to. He told me that I couldn't until I was 16. So, 16 became the year I would start smoking.
For some reason, it became a right of passage in my feeble little brain.
Well, I smoked until '79. We were living in Jackson, WY, and took the gondola up to the top of Teton Ski area, and I stepped off and walked to the summit.
I discovered that I could not breathe, anymore. I didn't get a good breath again until after we got back home that afternoon.
A couple of days later, I developed severe Bronchitis, and was laid up for almost a week. I decided that was the perfect time to quit smoking.
A couple of years of living in the Rockies, my lungs repaired themselves nicely. I've almost never had any respiratory illness ever since.