I think a good case can be made that becoming a critical thinker is analogous to learning a new language: as you start to develop this set of skills, you start seeing the world in new and interesting ways, expanding your intellectual horizon in unexpected and often delightful ways.
Of course, it goes without saying that being a critical thinker gives you tremendously powerful tools of intellectual self-defense against parties whose interests are not aligned with yours (and who might even want to manipulate and exploit you for the sake of their interests), but if I had to pick just one advantage of critical thinking, it would have to be the fact that it gives you the freedom to really be not only your own person but an even better and more thoughtful version of yourself.
Of course, all the intelligence in the world won't make up for ignorance or an absence of the values of honesty and open-mindedness... so let's roll up our sleeves and get to work :)
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