This comes from the most important question: Why we know what we know?

The answer is simple: because it was told to us to do so and we never ask questions why we should do it like that.

Same as the story of the chicken soup. Everybody knows that to start the soup, we must put the chicken in the pot and boil it. Then add the other ingredients.

A more deep thought in this article: https://philosophytalk.org/blog/how-we-know-that-we-know-what-we-know/