A lot of information is consumed without the consumers ever probing its origins or motives, and asking if it makes sense logically. They consume it by faith because it comes from “credible” sources. Credible: mainstream, sponsored, etc. For example, in geographical science, the theory that the earth is a globe, even though this phenomenon contradicts simple observatory evidence. You learn that the earth rotates and revolves, yet you see the sun and moon moves above you, and do not sense the earth move. Another example, modern history is a narrative of the elites of today. Ancient history is also written, not in full, to support or drive a certain agenda.
Thus, as a critical thinker trying to make sense of the world, you are left to bear the Burden of Proof. You almost always need to convince others that your theory makes more sense than the mainstream one (which at this point is considered law). And to make matters worse, most people are delusional. They do not care about what you say. They are okay following the mainstream narrative without questioning it. They are comfortable being driven as sheep to the slaughter.
What if you’d question everything you know? Some things would definitely be harder to disagree on, for example, the Fourier Transform and its use in telecommunication signals. But some things just require unlearning, applying observation and critical thinking using existing sources, and eventually forming a formidable opinion. At the end of the day, it’s an opinion you hold on to. It does not need to be accepted worldwide. It actually won’t be accepted if it is (or falls closely within the range of) the truth. But as long as others can see the trail of thought behind it, bravo, you are a critical thinker.
I’d rather a critical thinker any day than someone who regurgitates existing theories without having questioned them.