I quit smoking 5 years ago after smoking for over 10 years. I used to smoke a pack a day and I decided I was done with the smell and lack of breath. I quit on a Friday so that I would have the weekend to work out my anger etc. I remember crying the entire weekend! I didn't let myself pick up a butt I would just cry at everything. I also was unable to sleep soundly for the first month when I quit. I don't know if it had something to do with the nicotine coming out of me or what but just be prepared.
Once I got past that first month the fact that I could sleep again made me want to leave those butts alone. I didn't want to have to go through another month of not sleeping and I knew if I started again it was inevitable that I would also quit again.
As crazy as this sounds, I've decided that when I turn 80 I'm gonna start smoking again because by then who cares! This actually helps me get though every day smoke free. I'm not giving them up for good, just for most of my life.