It does not mean recklessness.

It means invulnerability.

It means a person has passed all the way through the worst thing they feared and come out the other side, and discovered, standing in the wreckage, that they can never be controlled again, because control runs on fear, and they have nothing left to be afraid of.

My father had taken everything he could.

He had not understood that in doing so, he had set me free.

Chapter 20 — The Three Oak Trees