Concentration

Cigarettes do not help concentration. That is just another illusion.
When you are trying to concentrate, you automatically try to avoid distractions like feeling cold or hot. The smoker is already suffering: that little monster wants his fix. So when he wants to concentrate he doesn't even have to think about it. He automatically lights up, partially ending the craving, gets on with the matter in hand and has already forgotten that he is smoking.
Cigarettes do not help concentration. They help to ruin it because after a while, even while smoking a cigarette, the smoker's withdrawal pangs cease to be completely relieved. The smoker then increases his intake, and the problem then increases.
Concentration is also affected adversely for another reason. The progressive blocking up of the arteries and veins with poisons starves the brain of oxygen. In fact, your concentration and inspiration will be greatly improved as this process is reversed.
It was the concentration aspect that prevented me from succeeding when using the willpower method. I could put up with the irritability and bad temper, but when I really needed to concentrate on something difficult, I had to have that cigarette. I can well remember the panic I felt when I discovered that I was not allowed to smoke during my accountancy exams, I was already a chainsmoker and convinced that 1 would not be able to concentrate for three hours without a cigarette.
But I passed the exams, and I can't even remember thinking about smoking at the time, so, when it came to the crunch, it obviously didn't bother me.
The loss of concentration that smokers suffer when they try to stop smoking is not, in fact, due to the physical withdrawal from nicotine. When you are a smoker, you have mental blocks. When you have one, what do you do? If you are not already smoking one, you light a cigarette. That doesn't cure the mental block, so then what do you do? You do what you have to do: you get on with it, just as nonsmokers do. When you are a smoker nothing gets blamed on the cigarette. Smokers never have smoking coughs; they just have permanent colds. The moment you stop smoking, everything that goes wrong in your life is blamed on the fact that you've stopped smoking. Now when you have a mental block, instead of just getting on with it you start to say, 'If only I could light up now, it would solve my problem.' You then start to question your decision to quit smoking.
If you believe that smoking is a genuine aid to concentration, then worrying about it will guarantee that you won't be able to concentrate. It's the doubting, not the physical withdrawal pangs, that causes the problem. Always remember: it is smokers who suffer withdrawal pangs and not non-smokers.
When I extinguished my last cigarette I went overnight from a hundred a day to zero without any apparent loss of concentration.