That fear, or phobia if you prefer, is the fear of heights, or acrophobia. I've had it as long as I can remember, and I'm sorry to report that it has grown worse over the years, not better. That's what makes living in Rockford perfect for me. There's nothing really high up to worry about.

Merriam-Webster online says this:

Definition of acrophobia:  abnormal dread of being in a high place, fear of heights

Yep. That sounds about right. During our 1995 visit to Paris, my dad and I headed over to the Eiffel Tower. My plan was to take a bunch of photos and take in the view--from the ground. I was secretly hoping that the Eiffel Tower would be closed for repairs, or that at least the elevators were offline, but no such luck. Which I knew would lead to this conversation with my dad:

Dad: Should we get in line to go up?

Me: Go ahead. I'll be in the gift shop.

Dad: The gift shop is at the mid-point level of the Eiffel Tower.

Me: In that case, I'll be wandering around down here waiting for you to come back down.

Dad: Oh, come on. We've come all the way to Paris, and you're not going to go up in the Eiffel Tower? Seriously? You know that no one has ever fallen from it, right?

Man walking by: Sorry, but that's not quite right. Several people fall or jump from the Eiffel Tower every year. A man fell just last week.

Dad: (Glaring at Mr. Info): Thanks for the help. Don't you have some schoolchildren to scare?

Me: (looking to slip away during this) Anyway, I'll be right over here when you come down...

Dad: C'mon, we're going up. Don't worry, I'll hold on to you so you don't fall.

Me: Dad! I'm 32 years old!

Dad: (grabbing my arm) Let's go, 32 year-old.

So, up we went. I got a great look at Paris from the Eiffel Tower--while my 72 year old dad held onto my belt as I went to the railing. I'm no doctor, but I believe my heart rate was at around 600 beats per minute. I also sweat enough up there to be worried about dehydration.

Anyway, back to our internet-sensation dad. He's got a major fear of heights as well, but he chose to deal with it in his own way while visiting Ireland's famous Cliffs of Moher. Kudos to a supportive wife and family for urging him on to internet stardom:

Coincidentally, I've been to Ireland as well. When we visited the Cliffs of Moher, I stood about 200 feet back from where you see this guy making his crawl to the edge, and I was still freaked out. It's a long way back down when your pants are wet--or so I've been told.