This is not the logic of most smokers I know (myself included). My reasoning, like that of most smokers I know, is:
1. I know how bad smoking is.
2. I know how hard quitting is.
3. I know the mental health effect of a quitting effort (whether successful or not) is challenging and unpredictable.
4. I have a lot of other challenges in life that incentivize putting off #2-3 until such a time as I think I can weather the storm and have a high chance of success.
Most smokers try and fail to quit multiple times before they succeed. It's a strong addiction, with a lot of negative emotional associations.