Most are probably fine, but I think the ones who make a big point of how they are autodidacts are usually also the really annoying kind; like the kind of people who have superficial knowledge of a number of subjects and thinks that makes them a genius, the person who reads the Wikipedia page on a topic and thinks they know all there is to know about it, etc. For example, one tends to run into the "philosophy guy" who has read (and misunderstood) something by Nietzsche or whatever and now thinks they have ethics completely figured out or who just reads a bunch of weird medieval latin stuff, accepting all of their proofs for god's existence without looking into the thousand years of critiques of these or how modern logic impacts them, etc. As bad as school can be sometimes, somebody taking some undergrad philosophy classes is going to gain a broader understanding of the subject than this. (Although, sadly, some people still manage to make it through an entire program still pretty "philosophy guy" brained).