I think I am allergic to the Hill Country. On a trip there recently, my allergies got stirred up in a big way. Perhaps it had to do with the trees under which we were parked that were raining down pollen and squiggles on our car and RV. Of course, there are different allergens up there than we have down here, and my body voiced its displeasure about them.
However, there are other things to deal with there, besides the allergens. I also do not have a good reaction to the hills and curves you must navigate when driving around. When you begin to crest a hill, you have zero visibility until you get over it. The same for the curves around the hills. You cannot see what is coming until it finally appears around the bend. A cyclist was in front of me on a street that had no sidewalks, so he was partially on the road. I dared not swing around him since we were nearing the top of a hill. I could not see what was ahead. So, I poked along behind him until the coast was clear. Another time, another place with hills, I came over one and had to brake quickly since a school bus was stopped right down the other side. I could not see it until I was almost upon it.