If anyone was addicted to tobacco, it had to be my father. For more than thirty years I never saw him without a cigarette in his hand. "I smoke because I want to," he would say. To which we'd reply, "Riggght!" At the age of about sixty or so he developed severe emphysema, along with a spot on his lung. The day he got the diagnosis he quit, and never smoked another cigarette in his life.
It's all down to what you value. For years he valued the pleasure of smoking more than he valued the distant and vaguely-defined prospect of disease and death. Once those prospects became very real and near, he decided that he valued life and physical well-being more than he valued smoking.
Some may say that after so many years, why bother? I say, that was brave and good of your father to quit. I’m sure it wasn’t easy.