What prevents learning?

Knowing.

You cannot learn what you already know. Learning is proceeding from not knowing toward knowing, so admitting one’s ignorance is the first step on the path to increasing one’s knowledge.

It is remarkable to me that many “developed” societies have evolved in a direction that makes this first step toward knowledge so culturally unacceptable.

My suggestion is to take a different tack: stop saying “I know” so often.