I am not sure that is so. I am pretty sure that for many smokers, perhaps most, they have no real understanding of what not smoking would be like. Most people who try to quit under the pretense that after they get over the hump they will be perfectly happy about being a nonsmoker probably do not realize that, having quit, they will miss the benefits of smoking. That is why most of them start again. That is a fairly foundational bit of our analysis.
That might be so, IF they had such a bad memory of times before starting smoking OR if they started smoking say around 3 or 4 years old.
You basically confirm my quoted statement with "That is why most of them start again." - iow, they know the difference, and validate the difference between before and after smoking. In order to differentiate, one must have something with which to differentiate.