I can’t claim to having coined that sentence, but Carl Jung can and it is worth taking some time to realise the implications…
We are what we think of most of the time so if we are telling ourselves “Whatever I do, I do not want to be like…” or “Don’t smoke, I must stop smoking” or “Right I am on a diet now so no chocolates for me, I will fight the hunger pangs, I hope I dont get too bad hunger pangs and loose control, gosh was that a hunger pang?”…etc Silly examples maybe but I am sure you can replace them with some of your own.
The fact is that when we resist something, we are thinking about it, that is where our focus is, our energy, our time and attention. We are so busy resisting that we are feeding with our energy whatever it is that we do not want , hence it is persisting.
If you are aiming at making changes in your life, on whatever level, make sure to focus on WHAT IT IS THAT YOU WANT, and not what you don’t want. All your focus, energy and attention should be spcifically aimed at what you DO want in your life. So imagine what life will be like with the change made, see yourself having achieved the change: what do you feel? see? hear? What is different?
Make your affirmations positive (stating what you want), present (under the motto: fake it till you make it) and personal (you only have the power to change yourself): I AM smoke free and healthy, I AM feeding my body with healthy, balanced produce..etc  I AM fitter every day…whatever it is.

Here is to making it happen! Good luck and keep me posted!