Doctors are just all the rest of us. Yes, they have educational levels that are more than some, and have spent a lot of time in training. However, just like the rest of the human race, they vary in their abilities in all kinds of ways. Not all graduated at the top of their class in school. And some have less than stellar abilities to relate to people. Some keep up with their training, and some never crack a book after they graduate unless they are forced to.
It is very wise and prudent to know as much as you can about your own health, and learn how to distinguish the bad advice from the good. It is self-protective and necessary.
I have found that the more haughty the doctor, the less they know. A good offense is the best defense. If they are obnoxious, you won't want to hang around and question them. But that is precisely the time when the grilling should start. But of course, it will all be for naught, if you don't have a clue about what you are asking.
So, read, read, read and learn as much as you can.