Thats just how I gave up. Had a nasty fluey cold in March and as asthmatic stopped smoking. (Always did with a cold, thought I could stave off a chest infection!!

)
Once the 'magic' 2 day nicotine withdrawal finished I wasnt going to start again. I think its breaking the habit is the biggie. I had aleady stopped having the first one of the day early on and was determined to stop it!
I have now done since 31st March 2008 9pm. I could still do the stress one now and again. I did put on a bit of weight, I put that down to my slowing heart!! (Last year resting heartbeat 110 bpm!!!! now 65 bpm) However I haved moved th'horse to be closer to home and doing more with him and getting fitter. My skin has cleared up, I dont have that awful hacking cough and back down to my smoking weight....
Like you say the cigarettes rule, I smoked for 20 years and now I'm free!
Went to GP for flu jab last week. The nicotine receptors in the brain apparently will go back into overdrive after 11 seconds of exposure

so will never be able to 'just have the one!' Just as well.
Good luck to anyone giving up, planned or not!