Briers has been very honest, as a lot of former smokers with smoking-related diseases are. He says he used to love smoking, but you have to quit in your thirties to avoid the risk of developing lung diseases later on in life. He says he only stopped at 70, and it was too late to avoid emphysema.
If he is dying now, and still loves smoking, he may as well light up again. I mean, the damage is done and he should enjoy the time he has left