I sometimes climb tall things because I like torturing myself.

And so there I stood in the skyscraper tourist lobby full of anxiety for the lurch upward to its stratospheric apex.

It takes $17 to ride the elevator to the 103rd floor at the Willis Tower, aged 39 years. Its cloud-splitting features, crowned the Western Hemisphere’s tallest skyscraper, rise 1,451 feet in the Midwest air.

Sidenote: You can buy merchandise commemorating the spectacle and experience of the Willis Tower before paying entry, and two or three times after viewing from the observatory, depending on what you consider a gift shop. This includes two opportunities to buy a picture they force you to pose for behind a bland background used for post-production Photoshop purposes. My group did not find the price of purchase near adequate enough for a comically bad picture of the four of us superimposed on the Moon.

My friends and I dictated our Saturday around the simple act of walking in a high space for some amount of time. Even walking a half-mile from the building itself sent my neurotransmitters into a sort of prophylactic state — a counteractive measure which I believe stops pant-wetting, or maybe even more severely (depending on how you severe you consider pant-wetting), catatonia.

If you fail in keeping up with the core of my subject, I speak of acrophobia, which reaches back to the origins of human consciousness. It starts with mans’ innate ability to detect danger in its multiform ways. It denotes the fear of heights, something one-fourth of the population deals with, although I find that coming up with a figure for something like this takes extensive guesswork. I find it more comfortable to just say that the affliction probably affects more than one person you know personally. And the suffix -phobia indicates an impact on a person’s daily life, in which case the language behind this and simply owning a “fear” can change the actual numbers a bit.

OK back to Saturday. I found myself maneuvering around in that four-sided observation deck with every physical tic an acrophobic may well externalize with exposure to the view, it apparently extends up to 45 miles in every direction (the folks in charge of customer satisfaction posted signs in the lobby saying observatory deck patrons do not receive refunds if the 45-mile technicolor view of Chicago’s skyline becomes compromised by fog, snow, dust storms, and so on. To me this seems unfair and a little like a museum’s art exhibit allowing paid entry into a window-less viewing room with the lights turned off, or at least unreasonably dimmed).

Except an impeded view did not factor in on this day, and before I could first summon the magnitude of more than four football fields between me and solid ground, I thought of the magnificence of civil engineering, of millions beneath me squeezed into the metropolis and buildings seen in Batman films.

Until this. See, the well-to-do decision-makers tasked with providing a memorable high-rise experience at the more popularly remembered Sears Tower spiced up the observation deck experience by installing a full-glass enclosure extending four feet outward from the tower, providing the sensation eerily close to walking on air.

Now, explanations in the medical field leading research on this fear of mine interpret my emotions as stemming from an unpleasant memory related to heights, of high-sensitivity to space and motion fluctuations, and even proprioceptive and visual stimulants all received by the brain failing to result in equilibrium for some people (e.g. height-fearers).

I believe in the sophistication of science to explain human tendencies and behavior. I believe whole-heartedly in genetic pre-dispositions to depression, alcoholism, and so on.

But my fear comes from simple pragmatics, not brain dysfunction. As in, even the slightest error from climbing a ladder to a certain height, an accidental push sitting on a patio rail, or that four-by-seven-foot all-glass casing becoming severed from its hinges – all result in an immediate and terrible death.

Height-fearers sense mortality at every corner. We look up at the ledge from the ground and see danger, the people standing on the glass, ant-sized above. We drive in cars down roads and see death seconds away. And do not ask us about seat belts in airplanes.

I crept closer to the glass. People took pictures on cell phones. The people ahead of us left.

I stepped in and looked down.