Different behaviours & circumstances release "feel good" chemicals in our brain...seratonin, dopamine, oxytocin & endorphins. To some degree, depending on
how & why you smoke all of these feel good chemicals can be triggered by smoking. Subsequently a pathway is developed in your brain to stimulate these
chemicals associated with smoking. Nicotine plays its part to a degree, though it is my belief that nicotine doesn't make you feel good. When your body is depleting its nicotine stores it makes you feel bad. Replenishing stops the bad feeling. the actual act of smoking is what stimulates the happy chemicals. Over years of reinforcing this pathway 20 or so times a day, the "pathway" becomes a multi lane expressway, your direct route to those "happy chemicals". Then there is the "unhappy" chemical cortisol, which is also necessary to protect us against danger both physical & emotional. I'm of the belief that, when encountering a series of adverse situations, I generate a surplus of cortisol which results in anger, depression or anxiety. My rational brain KNOWS that smoking won't fix things but instinct & years of reinforcement directs me down that 6 lane expressway for relief. So wherein lies the solution? Build alternate pathways for the happy chemicals. Reinforce them until they become as big or bigger than the 6 lane smoking freeway.