I believe it comes down to two things. Emotions or overindulging in alcohol.
What was it for you the last time you lost a quit?
and,
What is your plan so it doesn't happen again?
Why not talk yourself out of smoking? It requires no more effort than talking yourself into smoking.
The last time I lost a quit was twenty some yrs ago and it was because of one too many drinks! But this quit is heading for three glorious yrs and it's because I have the right mindset and I have had since before my quit date because of this site and all of the reading and preparing for my 1st day and I was willing, determined and totally committed to succeed and with vigilance I will continue to live a life of Freedom, thanks Dale.