We can so easily, accidentally forget, especially if it was convenient and saved face.
I found I had to reinforce things in my life, by repeating them until I could believe them. Affirmations is a good example, and for me it was
How It Works and the Preamble in the AA's Big Book.
AA PREAMBLE
Alcoholics Anonymous is a fellowship of men and women who share their experience, strength and hope with each other that they may solve their common problem and help others to recover from alcoholism. The only requirement for membership is a desire to stop drinking. There are no dues or fees for A.A. membership; we are self-supporting through our own contributions. A.A. is not allied with any sect, denomination, politics,organization or institution; does not wish to engage in any controversy; neither endorses nor opposes any causes. Our primary purpose is to stay sober and help other alcoholics to achieve sobriety.
http://www.aa.org/bigbookonline/en_bigbook_chapt5.pdf