While watching the Witcher on Netflix, the phrase "it's magic, it isn't real" troubled me.
Then I realised that it was the literal truth of magic.
When Yennifer created quills from nothing, they were visible to all. They would be added to arrows, the archers would weild them. All that mattered was the target, the arrow and the archers belief that the quill would guide the arrow to the target. If you believe that things will work out as you expect them to, you have a confidence that guides your aim.
When the guys slung the bottles of explosive toward the enemy for the female archers to hit, you might not believe that an arrow could hit a bottle from so great a distance. They did.
So much of our interaction with reality and each other is based on magic. Our expectations of each other is the basis of commerce, self worth and relationships. They aren't real and weigh nothing, but our lives revolve about them.