Skydiver with a Fear of Heights

Today something happened that baffled me to no end. I go along out into the field to do a survey on this one sign with one of the installers and we take the big bucket truck along to survey this sign that's about 20 feet up in the air. We hop in and get up to the sign and I am holding on for dear life. Mr. Skydiver, 75 jumps in the book from over 3000 feet, is afraid of being 20 feet off the ground. Of course the basket is not level, swaying in the wind and the controls only respond about half of the time. But its only 20 feet above concrete and a barb wire fence. It really made me wonder how I could have no problem jumping from planes and when it comes to something little like this I could be so fixated on the potential to fall to my death. I guess its my fear of ironic death. I can only imagine at my funeral how many times two people would whisper to each other, "Fell twenty feet and died after jumping from planes without any problems, that's just ironic" That would be far worse than just plain old sympathy.