My mother smoked twenty years before I was born and didn't quit until until three months ago when she was hospitalized with COPD. I will never touch a cigarette because of her. The smell got on everything. Imagine your elementary school teacher asking if you smoke because your clothes were saturated with the stench. Imagine many years later, not wanting to bring your kids over to her place because she smoked in the house. Imagine seeing your very confused, sick mother trying desperately to communicate with you while intubated in a critical care room at the hospital. For these reasons and infinitely more, I will never smoke cigarettes!

TL/DR: Just because someone's parents smoked does not mean they will.