from magazine article by Susan Gregory Thomas, How to Make Time for Yourself

When I was 15, my family moved to a cottage in the country for a year.  The property had an expanse of woods that led to an open meadow.  One day I decided to take a walk through the woods alone, away from my endlessly talky, frenetic family.  I remember thinking that when I arrived at the field, I would lie down, look up at the sky and just be.

So I did.  After a few minutes, I felt myself-my ego, thought I wouldn't have called it tat then-start to evaporate.  It was just the sky, silence, my body.  I panicked.  I didn't feel at one with the universe; I felt a terror of slipping into the void.  There, I, "Susie," would no longer exist, but instead would dissolve into something cosmic and unknowable.  I leaped up and shot off like a deer.  I couldn't wait to bicker with my brother.

It turns out that mine was not a unique experience.  Meditation, quiet contemplation and prayer can sometimes have similar effects.  The 16th-century reformer St. John of the Cross called this terror of the void the "Dark Night of the Soul," and in writing a treatise of the same name, he argued that God, as a necessary step in purifying the souls of people in deep prayer, "strips their faculties, affections and feelings, both spiritual and sensual, both outward and inward, leaving the understanding dark, the will dry, the memory empty."