Well, mine is kind of silly but when I was little my dad taught me fear of falling, heights, injury, etc., by holding me off to the side while my brother did anything he wanted and we watched. He was petrified that I'd get hurt. Now I am incremently conquering those fears mountain biking. The latest trick? When my brain starts to take control, I just shout at my brain, "Stop It, Just Relax!!!" Sometimes it actually listens and then, I get all teary-eyed when I conquer something that's just stumped me before. It's incredible what illogical child lessons reach out and take control later in life.