I’m playing a word game.
You can receive knowledge from books or teachers.
But you only learn by action. Action (you), reaction (the world). Now you have learned something on your own, that you—uniquely—possess. And I mean you possess it in a way no one can steal.
Can anyone steal your ability to spell, to multiply numbers? To walk?
Faith without works is dead, says the New Testament. It’s like that in all facets of life. Learning is an iterative acquire/test/refine loop.
Learn by doing.