A key problem in politics $--$ indeed, in many situations $--$ is that people form, hold, and express ideas, often quite vigorously, on the basis of what they know, even if what they "know" is incorrect, inaccurate, incomplete, inconsistent, inapt, irrelevant, distorted, or such.

only on Tuesdays

no way. I know what I know and that's the whole story.

yes, because personal experience and logic illustrate that this is so