I think you should ask the question: "Why do people start to smoke".
First of all smoking is highly addictive and it is much tougher than you think to stop. Second, once you have acquired a taste for smoke there are several benefits. It does taste good (at this point), it satisfy the chemical dependency and the relaxing feeling that goes with it really does feel good.
I started smoking at a very young age of just 6 years old. My motive was none other being the "big" guy. I smoked for 23 years before I finally had an incentive to give it up that was greater than the addition.
One of the pleasure of smoking is that of relaxation. The carbon monoxide (CO) in the smoke binds itself to the iron in the hemoglobin molecule in the read blood cell. The hemoglobin is designed to transport oxygen to wherever in the body it is needed and it will transport back completely oxidized carbon molecules (CO2 or carbon dioxide), which are exhaled. The CO in smoke bonds to the hemoglobin in a much stronger bond than O2 or CO2 forming carboxyhemoglobin. That bond is so strong that the hemoglobin is prevented from transporting oxygen for a while, giving the smoker the sensation of asphyxiation (or relaxation), deprived of oxygen.