I am afraid of heights, but only when I am standing on the ground. Reverse vertigo.

I was five the first time I felt the terror of this condition. I suppose it was my sister (or perhaps it was an older cousin, though this does not matter) who took me to play at the park in Madelia that day. I saw the swings and the slide, the merry-go-round and the seesaw. But I also saw the watertower, its four legs splayed on the corners of a giant cement platform on the far side of the park, its center column, a ladder, rising up to the underside of the tower's great belly.

It was not the first time I had seen the watertower. This, in fact, was the landmark that told us kids our hours in the back seat of the car were almost over, that we were almost to Madelia. We played at who could spot the watertower first, who could see the silver teapot with the red cone-shaped lid rising above the thick green trees of Minnesota's flat landscape. And when finally we did see our landmark, we sang to the tune of that age-old playground taunt, "I see the watertower, I see the watertower!"

But I had never seen the watertower up close, and that day in the park, I let go of the hand that held mine and ran past the playground. I ran to the center of the watertower's base, and I looked up.

At first, I thought the flat silver circle miles above my head, miles above the tops of the tallest trees in the park, was moving, swinging around and around in great, lazy arcs, but when I felt my knees buckle, I realized my head was swimming. I felt sick, dizzy. I closed my eyes, then squinted at my sandals to steady myself. Afraid to look up again, I walked a crooked line away from the tower's platform, back towards the playground.

For a long time that day, I sat in a swing, grasping its chains and listlessly kicking at the playground gravel. From this distance, I could look up at the watertower and not be afraid, not feel small and sick. But something of power touched me that day, something that still keeps me from flying kites, from squinting at the sun, from confronting mysteries larger than myself.