In order to quit smoking instantly, You have to have a very good reason with a big impact in your life. The worst one would be to suffer from bad health and illness by you or someone around you that was caused by your smoking. Then you'll realize you have to stop soon when it's too late. If you know better than this and you believe that you still have the discipline in yourself than please don't wait for this to happen. Like they always say, prevention is always better than cure.