Critical thinking is acknowledgement of the possibility that you could be wrong, that you could be mistaken.
And anybody can be wrong. You can be right too, but how do you know you are right?
The scientist (ideally!) realizes (i) that a proposition could be wrong, and (ii) (more likely) he or she could be wrong. Therefore, the scientist (and I am careful to use a gender neutral noun here) devises experiments that rigorously test the proposition that is advanced. An important feature of a scientific hypothesis is thus its so-called
The late Richard Feynmann once proposed that a good scientist is skilled at the art of crap detection. Obviously, the skill can extended beyond science.