“There was this incredible crashing noise, like a huge stack of heavy boxes falling over. I went running around the house making sure no one was crushed and never found what it was. Then it happened again that same night. Again, nothing had actually fallen over.” My brother is one of the first people I tell strange phenomena to, because he is the likeliest of all my family and friends to explore all the possibilities with me.

“Whoa. Ghost?” He seems concerned, but practical.

“Maybe a poltergeist?” I actually sound a bit hopeful.

“That doesn’t seem like it would be comforting.”

“But it is!” I can sense my brother raising an eyebrow over the phone, “Poltergeists, well according to Wikipedia, tend to be manifestations of one person’s stress. So, I just need to relax. If it’s a ghost or something then I have no control over bumps in the night. This way, I do!”

“Yeah, still not a comforting thought.”

I would rather have a poltergeist in my house than a ghost. My brother would rather a ghost than a poltergeist. My oldest son, when asked if he was afraid of ghosts one Halloween, furrowed his brow in confusion. “Ghosts are just dead people,” he said. Seeing as he is generally not afraid of live people, this makes sense. But it doesn’t.

Fears are so idiosyncratic. I used to believe that every fear someone had made sense, or had a contextual backstory that explained it away. I am scared of crossing train tracks. I live in the suburbs of Chicago and there are a whole bunch of Metra stations and tracks everywhere. I had heard stories of people dying at crossings. When I was a child in the backseat of a mini-van, I had no control over the speed of our car or when I could cross to safety. When I have had to walk over tracks, I am painfully aware of how slow and clumsy I am.

I am scared of large dogs because for a few summers I worked as a mail carrier. A huge German Shepard that roamed an otherwise empty house day in and day out lunged for me and ripped through a screen next to my head.

I still have nightmares about velociraptors because of Jurassic Park.

These fears make sense.

But I am scared of heights with no clear reason. Arriving late for almost anything starts a low-level anxiety pit in my stomach that can grow quickly to fill my chest cavity. I can swim, but drowning fills my nightmares.

I’ve come to realize that some fears have no clear context, that maybe the quirks of what we fear are largely inborn. Just like our favorite and least favorite foods are decided by a mysterious combination of the chemicals in our brains and the way we’ve been exposed to snacks, maybe our fears work the same way. Some make sense and others don’t.

Take my two sons. They are only two and a half years apart. Almost all of their formative life experiences they have had so far in this world have been together. Raised by the same people, taken on the same vacations, enrolled in the same school, exposed to the same movies and TV shows and video games, they probably have more similarities than differences. But…

The oldest hates rollercoasters, but loves huge water slides.

My youngest loves rollercoasters and HATES water slides.

My oldest is afraid of spiders and heights.

My youngest will be going to a camp this summer mostly to see spiders, and climbs to the top of every playground.

My oldest went water tubing at the age of six and stayed out behind the pontoon boat as long as we would let him.

My youngest, sitting on the boat, absolutely refused. But when he saw teenagers jumping off cliffs into the lake he asked if he could, too. At four.

At the very least it fascinates me to know that for almost every fear we have, rational or not, there is probably a counterpoint. For every fear that has us paralyzed, there is someone who is just amazed or thrilled by it. And the things we take for granted as manageable (I am not afraid of dentists or doctors or public speaking, for example) could be terribly daunting for someone else.

I have always been terrified of the idea that aliens may exist. I want to watch shows about it, but find myself chickening out at the last moment. At any given time there is probably an episode of Ancient Aliens waiting for me in the DVR, biding its time until I am brave enough to conquer it.

My oldest, at eight, has commented on that particular fear of mine.

“I am much more worried that there are no aliens. That will really are alone in the universe. That scares me. We’re the only ones alive in the whole universe? Totally by ourselves?”

I consider this for just a second. “But, what if they are dangerous or evil aliens?” I ask because that is the only possibility I can imagine. “If those are the only creatures who are out there, that doesn’t seem very comforting.”

“But,” he looks at me with that furrowed brow again, “it means someone else is out there. It is.”