My Grandfather smoked his whole life. I was about 10 years old when my mother said to him, "If you ever want to see your grandchildren graduate, you better stop immediately." Tears welled up in his eyes when he realised exactly what was at stake. He gave it up immediately. Three years later he died of lung cancer.
It was really sad and destroyed me. My Mother said to me - "Don't smoke. Please don't put your family through what your Grandfather put us through." I agreed and at 21 I have never touched a cigarette.
I must say, I feel a very slight sense of regret for never having done it, because your post gave me cancer anyway.