Fear of Heights
I have had a fear of heights as far back as I can remember (60+years!) but it is of "open" exposures. I have been to the top of Sears Tower when it was the highest building in the world and had no problem looking out, but felt very uncomfortable two weeks ago getting onto a glass sided escalator crossing the void at the middle of a shopping centre. I have never had a problem with flying or most mechanical transport, I loved crossing the Forth Bridge, by train, as a child, but would not have wanted to walk across!
I don't mind high places in a train but get spooked in a car, so there may be an element of control freakary!
The silliest experience was flying IFR but in the clear, in a Cherokee6 with a fellow controller who was also high hours PPL. As we levelled at FL50 over the Needles, on the Isle of Wight, we could clearly see cars making their way along the cliff road out to the point. Looking at these people from 5,000 feet above them, we both turned and uttered the same thought to each other, "you wouldn't get me up there!"
All perspective and it can change!