Anna Salamon and I are confused. Both of us notice ourselves rationalizing on pretty much a daily basis and have to apply techniques like the Litany of Tarski pretty regularly. But in several of our test sessions for teaching rationality, a handful of people report never rationalizing and seem to have little clue what Tarski is for. They don't relate to any examples we give, whether fictitious or actual personal examples from our lives. Some of these people show signs of being rather high-level rationalists overall, although some don't.
I have a different way to look at this question. (1) introspection is bunk (2) if someone asks us or we ask ourselves why we did something - the answer is a guess, because we have no conscious access to the actual causes of our thoughts and actions (3)we vary in how good we are at guessing and in how honestly they judge themselves and so some people appear to be clearly rationalizing and other appear less so (4) most people are not actually aware that introspection is not direct knowledge but guesswork and so they do not recognize their guesses as guesses but may notice their self-deceptions as deceptions (5) we do not need to know the reasons for our actions unless we judge them as very bad and to be avoided or very good and to be encouraged (6) the appropriate thing in this case is not to ask ourselves why, but to ask ourselves how to change the likelihood of a repeat, up or down. Although we have only guesses about past actions, we can arrange to have some control over future ones (7) the more we know about ourselves, others, our situations, science and so on the better we can answer the how questions.