I wouldn't say negativity as much as trying to point out the pitfalls of constantly telling yourself "it's JUST a slip" I told myself that for the last 10 years I had been trying to stop drinking in my 20 year drinking history. And what happened was, I started to get so demoralized with myself, I doubted I had any more "pick yourself ups" in me.
Everytime I went into the whole stopping drinking thing, with the attitude that I would probably slip up sometime given the past attempts, I had kneecapped myself from the start.
I know, after the last 10 years of trying instead of doing that if I ever drank again, I'd probably just accept my fate and give up giving up.