Actually this is in the 12x12, I do not know the page #. Before the traditions were developed, an AAer with a lot of energy and drive started a group that tried literally to be all things to all people - AA, job training center, social club, gym, bank - and I mean this literally. They drafted up 61 rules to make everything work.
When the whole house of cards came tumbling down, the AAer sent Bill Wilson his new rule, rule 62: Don't take yourself too seriously.
Here is a link:
Alcoholics Anonymous: Twelve Steps and Twelve Traditions, Tradition Four - Nashville Recovery