Quitting smoking

I gave up smoking cold turkey when I was 27 for approx. 6 years. At 33, I went through a messy divorce, I started smoking again. One or two here and there, then eventually a whole packet while drinking. It started once a week and then twice a week and sometimes more. Eventually I gave up again (and my new husband) in 2018 – we don’t smoke other than when we drink. Then while travelling last year we started doing it again. Then we stopped for 6 months and then we started again. I’m on a rollercoaster with this habit. There’s part of my brain (when not drinking) that says, “hell no, never again.”  Then there’s the other part of my brain (after 3 or 4 drinks) that says, “It’s just this one time.”

What is my brain doing?