I feel your pain. It does get easier, but I have slipped in the past even after long periods of time.
My favorite cigarette ever was after I quit for 5 years. Then my mother came to visit one day and she left her pack of smokes at my house. I looked at them for a while, took one out and sniffed it as I glare at the remaining open pack. Fascinated by the shape, I twirl the pack in my left hand before discarding it a waterlogged trashcan by the garage. I then walked out on my back deck and picked up the lighter from my grill. It was a April day and the breeze was just magnificent. I lit the cigarette while leaning against the rail of my deck. The warm gentle wind wisping the beautiful white smoke closer to the pine trees creating the perfect contrast in color.
I puffed on the cigarette a 2nd time and as I inhaled noticed the rays of sunshine streaming toward my face as my toes felt lighter.
That night I only had happy dreams. Dreams of rainbows, butterflies, breast implants, and interior latex paint.