(Forget who the author is so cannot make an attribution, but found this excerpt helpful long-term for my Quit.)
There is another important phenomenon that happens long-term that can challenge your resolve. Although you think about smoking less often, when it does happen, you tend to remember only the "good" cigarette or the things you enjoyed most about smoking. You forget how most cigarettes made you feel such as the ones you smoked automatically without paying attention to them, and the nasty ones you despised as you smoked. You also forget about all the associated annoyances that went with being a smoker such as not being able to smoke on planes, the smell on your clothes and hair, having to buy cigarettes in the middle of the night, and so on. The trap is you think of smoking in terms of the best moments you ever had smoking. If you focus on that image without reminding yourself of all the negative aspects of smoking, it is hard to not want one. This is the danger with urges that occur weeks and months after you've quit.
The "good cigarette" concept is a fantasy. Not smoking will never be as good as that fantasy, but smoking will never be as good as that fantasy either. Remember smoking for what it was like at the end--the day you quit--not what it was like early-on when it initially hooked you. In the end, smoking was annoying enough to make you want to quit, even though you were going through a horrible withdrawal and psychological readjustment to do it. You understood smoking was making life complicated, ruining your health, and slowly killing you. Cigarettes haven’t changed, just your memories of them.