I smoked a pack a day for 2 years or so. Some say that isn't enough time to build up an addiction to the level is hard to quit, but I beg to differ. I "stopped" smoking about 10 months ago. Since January I have bought 5 or 6 packs, three of which were for one weekend of camping in August. I haven't bought a pack since then. I still have a cig here or there when I am with my friends and they offer me one. I have however been dipping skoal for a year and half now or so, and I find that way harder to quit than smoking. The fact that I can do it anywhere makes it really hard to stop. I can be at work, in the library, or just chilling in my room, the fact that I don't have to go outside makes it difficult.
I had an alcohol issue for a while post fall. I wasn't at the point where I would day drink, I was drinking 4-6 nights a week, but when I mean drink I mean all out. I would kill a 6 pack in half hour or kill a 750ml of vodka just as a pregame. I haven't quit drinking, I get drunk maybe twice a month now. However, it's no where even close to the level it used to be. I'm a big dude, so I'll still drink 8-10 beers over the course of a few hours, but thats nothing compared to the nights where I would slam down 18 and still want to keep going.
I smoked a lot of pot over the last 6 years. I would go months at a time without ever having a non-stoned moment while awake. It didn't really affect anything other than my wallet. Since school started this September, I've toked maybe a total of 6 times.
So far this semester I have three A's and two A-'s. I have never done that well in school. I wouldn't say it is 100% due to not smoking so much, but it probably helps. I'm not hungover while trying to stay awake in class. I spend at least 40 hours a week in the library, which is something I've never done. I also now have a girlfriend who I started dating in July, and she just gives me an overall postitive attitude toward life... something that I didn't have for the longest time. I don't think my curret success could be attributed to any one thing, I'm sure it's a combination of all these things... I'm liking it.