Also:

• The phrase "the people who mind don't matter and the people who matter don't mind". Similarly, the phrase/meme "haters gonna hate" (edit: although that usually has further information implied).

• Possibly the saying that if you're worried you might be crazy, it proves that you're not. (Although the problem with that could have more to do with taking your conclusion and adding it back to the evidence pile, ala One Argument Against an Army.)

• "And people do stupid things no matter what -- beer or grass or whatever are all incidental to that central fact.". That's fits under "predestination fallacy", but possibly not the concept I was originally thinking of, which was something like "argument by subtly-flawed categorization".

• "If I lied the first time, I'm not going to tell you the truth just because you ask twice.".

I'll edit this post with any further examples. Last edited 2010/11/07.