My own feeling about the far too many self titled skeptics that I deal with online is that they’ve not really learned to be appropriately skeptical. The first and most important lesson for a real skeptic is to acknowledge that it is no longer possible, if it ever really was, to be a “renaissance man” or a fully rounded autodidact.
There really is a limit to how much of the available knowledge and skill in any given topic a non-expert can acquire. So the first responsibility of being skeptical is as accurate an assessment as possible of one’s own expertise.It really doesn’t matter how clever you are or whether you’ve acquired advanced qualifications of various sorts. Knowing everything is just not possible and you mustn’t let yourself fall into the trap of thinking you can know everything.
To be thoroughly and conscientiously skeptical, you have to develop the skill needed to judge the value of the baying hordes of people claiming expertise in all sorts of areas. If you prefer to say that you can’t venture an opinion until you’ve worked whatever it is out for yourself, then you’re abrogating your responsibility to stick with properly evidenced positions. You simply cannot check all the work of all the astronomers and microbiologists and road builders and physicists and veterinarians and sociologists and epidemiologists and car mechanics and agricultural hydrographers and your own doctors, you have to pick and choose.
It’s how well you pick and choose the experts you will listen to and how you go about judging the quality of the evidence you rely on that makes you properly skeptical. Not a cynical dismissive waving away of everything you’ve not seen with your own eyes or worked out for yourself from first principles. That’s not skeptical. That’s being arrogant or suspicious or untrusting or fearful or some mixture of any of those.