For me it's flying. Put me on a plane and as soon as the wheels are off the ground, I turn into a panic stricken quivering wreck. I'm afraid of heights in general but I can normally handle myself on the rooftop of a tall building or on a mountain. Zipping through the air at 35,000 feet going 600 mph just turns the fear knob in my brain up to 11.
So what turns you into a useless heap of fear?

