It's all in the mind. I think that a small pocket of hope/wishful thinking will undermine your resolve if you are not careful. Was on a BWI flight some years back and was resigned to 13hrs smoke free. On-board it turned out that you could smoke in the back 4 rows (1998-ish). Lady in front saw this and then couldn't settle, constantly looking round (over my head checking out if a seat had become free). Patches + gum + morose resignation is a winner.