I agree with those who've indicated that you have not yet committed your mental/emotional self to quitting, even though you've conquered the physical aspects of quitting for all those 16 months now.
I suppose we're all different in how we process those mental/emotional aspects of quitting so it's hard to say to others; do this or that and your desire to smoke will be gone.
For me, it just happened one day about 7 months into my quit. I was on holiday in Las Vegas of all places and it seemed everyone was smoking. Heck, people were even smoking while in the hotel pool - literally standing in the water smoking. Instead of envy, I only felt pity for them as I watched them smoking one after the other cigarette and I've looked at smoking that way ever since. I feel sorry for people who are driven by their addiction all the time no matter what else is going on around them. Smoking is literally robbing them of their freedom to live life positively.
After years quit now, I still will get the odd thought that I might like to have a smoke. No idea where or why those thoughts come from they just pop into my mind but they are just that - brief, fleeting thoughts. I quickly catch myself thinking; where did that come from? Then, the thought is gone and I just carry on. I'm not sure exactly how I reached this point in my own quit but I do know this; I have always remembered why I quit and the strength in commitment it took to do so. I have also always focused on the positive things I have received in my life since quitting and I have never again thought that lighting up even one smoke would do anything positive for me. I'm both happy & proud that I was able to deny my addiction and have focused only on a future life without those freedom stealing cancer sticks!
Why did you quit? There must have been a reason that was compelling enough for you to endure all the struggles we go through in those early days/weeks/months. Does that reason not still exist for you? What is it that you think lighting up again would do for you? How would it improve your life and would you be willing to give up the positive things you have noticed in your life since quitting? Perhaps some concentrated self examination of these questions might help you to adjust your focus toward the benefits of being quit and away from the mirage of smoking positivity we smokers seem to create within our own minds.