THIS. Let me drop some science on your ass. Nicotine is addictive because it basically stimulates your entire nervous system. Not just the brain. Think of the nerves in your body as a network of highways. The toll booths are intermediary between different regions. These are the receptors where a certain chemical works for the nerve impulses to go through. But nicotine also works here. Giving cigarette nicotine to the body is like giving a $1000 at the booth to whiz through at ultra high speed. See, the nerves themselves don't do anything. They carry a yes/no signal. It's where they end up is what defines the action. So if you're sleepy you're saying no to one circuit and if you're horny you're saying yes to another kind of circuit. It's way more complicated than that, but the idea is that opening the flood gates with nicotine makes you hyper stimulated which gives you a head rush. The first time you smoke, there's a rush you feel which you constantly want to resimulate. But that rush may never come, instead you get used to that level of stimulation that you need it. Quite like coffee, except exposure of nicotine to your sensitive toll booths is highly, dangerously addictive. The worst thing is, your body will never forget how it feels on nicotine. Even if you're a 10 year quitter. Even if you've recovered, your body still knows. And thats why cigarette quitting is the hardest shit in general terms. It's not just you, its the way your nerves respond to nicotine. So try as you might, once a smoker always a smoker. Never pick up a single cigarette kids. They might be doing it, but value your own body.