Heights and enclosed spaces. I have no explanation for either. Been this way ever since I can remember. At shows, I think the best place to watch is the front row of a balcony, but it is only well after intermission that my toes start to uncurl and I stop trying to grip the floor. Even when I watch other people who are up high, my toes curl. Oddly, I have no fear of flying in an airplane. In enclosed spaces, I have to fight the urge to hyperventilate. And don't expect me to step inside a glass elevator. I'll take the stairs, thank you very much. (Usually, though, there is also a regular elevator in the same building.)