[Mollocephalus]

You must know very well that addiction is not only pshisical, but psychological too. Some people, which i'm pretty sure excludes you, now that you've decided to change, know no better. They do drugs to fill some major mentality/personality flaws (or what their subconscious perceives as such); they keep doing them cause the drug brought them to think they want it. It's a very personal matter and it changes from person to person, and mine are mere speculations. But in all honesty, from the lighter to the hardest drugs, the bottom line is always the same: learn to respect and love yourself for who you are, and you won't need any of that shit.