These initially harsh images are reflections of the the way the truth affects the individual - far from a gentle awakening, the truth often explodes in our minds, blowing everything we have previously known out of our heads. That's what it means to be struck by the truth. It rearranges our heads, it empties us completely. Awakening and enlightenment are not soft calm realisations - they like a bullet to the head. And there is no going back. 

I understood the symmetry of stone on stone;

The elegant wind of the stair, the steepness of the step;

The swiftness of a summer day to storm,

and the whiteness of my own bone.