Sorry for delayed reply. "I like pink" is an assertion of a preference, rather than an opinion about a fact. (Well, I guess it's asserting the fact that you like pink... and stuff like brain analysis may help test it. ;))

Well, yes, some are difficult to test... but then one can argue the reasoning for having them.

Oh, just to clarify, I was proposing a sort of 5-second-meta-skill of "remembering your rationalist knowledge/skills when you need them", the "remember politics is the mind killer" being an example rather than one I wanted to single out.

*blinks at the edit* erm? disregard which part/aspect of it? (ie, are you retracting a claim, or...?)