OK, i made an account just for clearing this up for anyone who still feels confused.
I did a lot of research about smoking.
A brief summary:
As any drug it has an affect that feels positive for the ones tolerable to sustain the immediate intoxication.
It gives you an adrenalin rush and improves digestion.
The intoxication through lungs gives immediate effect on the bloodstream, brains and nervous system.
How harmful is smoking really?
Immediate:
damage and "coloring" of teeth, mouth gum, throat, lungs, skin and nails.
Smell and sticky tar all over the hands, hard to wash off (except when smoking with an adapter). Major decrease of physical stamina. Anxiety (or in other words "ready for action").
People who are not yet "hooked" feel dizzy, anxios, want to cough and might get sick and even throw up when they smoke.
When this effects are gone and feeling bad when smoking is gone, the so-called resistance of the organism is build, and with it- addiction.
Long-term:
Increased risk (high bids on lottery of getting sick with

lung, skin, mouth, troat cancer
(google 'em, scary sicknesses).
Heavy or PERMANENT damage to the lungs.
Increased chance of nervous system disorders.
Vain damage.
The list of toxins and their effects in cigarete smoke can be foung online.
Passive smoking also gives you free lottery tickets for all the sicknesses mentioned above.
Why do we smoke?
-- Social- cigarette companies spent 100 of millions to build a good image of smokers
(Schwarzenegger, Jack Nicolson, Humprey Bogard, Marlboro Formula Racing, Cowboy movies)
Smoking in a bar is still fashionable, you look good puffin that cig, but your breath, hair and hands smell. The girl or boy you want to look good for should definately like this odour...you get the point.
It is tough and hard to decide not to smoke when in a social circle of smokers, and people who do that, deserve the credit.
-- "Need a brake" - getting fresh air and smoking at the same time is actully funny absurd.
-- "Relaxes" - only psychologically. The cigarette does not have any medicinal relaxation effect, on the contrary. The relaxation comes from the "inside" the person, not from the
smoke. Taking deep breaths would have a better effect.
-- "Clears my head" - more like putting nitro instead of normal petrol in a car- it will innevitably make the engine do something it is not supposed to. Coffe, green or black tea are a better alternative, but do not work as fast since not consumed through lungs!
-- "A habbit" - habbit plus addiction gives a feeling that smoking is a part of one's identity.
-- "Smoking ocationally" - a biggie, dependant on personal resistance to building habits and addictions. That is why some people can smoke "sometimes" some not. Better of not trying to find out where you want to be, you would be bidding on a liability.
-- "Makes me feel fit" - subjectivelly and short-term. Smoking has no long-term physical benefit. Rather try stamina sports.
-- "I like danger and being edgy" - may i suggest martial arts, stunt sports, mountain climbing? All the things that smoking would make a little more hard to do, since it has all something to do with stamina.
-- "Taste" - the flavor is mainly in the cigarette paper. Parfume and aroma are chemicals. Raw tobaco hardly tastes better than any other random plant.
-- "Pleasure" - if you really like watermellon, do you carry it around with you at all the times? Addiction removes the "i had enough of this for a month or so" barrier in our brain.
Bottom line:
The benefits of smoking are "all in the head"- our heads are very different from each other.
So the story and intepretations are different.
The sience behind smoking is simple: smoking has not one long-term physical benefit.
Hardly will anyone ever force you to smoke.
If you do smoke, then just make sure you really enjoy everything about this activity, not do it for reasons wich you do not comprehend. (like: why do i even spend money on sigarettes???)
And more important, stop smoking at all costs if you realise that you dont like it anymore.
Thats it from me.
Good luck!