I don't smoke and never have. I hate the stench; I worked as a nanny for a family where the dad smoked. I would come home and all my clothes would reek, as would my hair. They live across the street from us and when their front door is open the scent wafts across the street. Their little girl, who was then 3 or 4, had asthma. Every morning I had to administer three shots of two different types of inhalers into her mouth, and despite that, she would cough like crazy. Sometimes when their windows are open I can hear the dad (the smoker) coughing. Makes me sick just thinking about it.
My grandpa smoked; he picked up the habit when he was in the army circa WW2. One of my earliest memories of him was of him carrying his inhaler around with him in shirt pocket. By then he had quit, but years of smoking had already done their job. He died two days before I turned four... heart attack.
Sufficed it to say, nobody in my family ever took it up after seeing what he went through.
If you want to quit, and plan to quit, what are you waiting for?
Hmmm I think I kind of sounded like Lois in The Phoenix, just then.

But seriously. Why not? Your body will thank you and it makes for one less thing you have to do down the road...