Reminds me of swimming lessons.  I learned from a Red Cross course in my town when I was 5.  I was like a fish in water!  Always was a great swimmer. 
Now, my mother never was taught how to swim, and she was terrified of water (that's why she enrolled me at 5 to take swimming).  Also, hubs never learned how to swim either, and he tried to learn a little, a few years ago, but bailed.  Just couldn't get the coordination together, and I think fear set in.  Yup, it's a whole different learning curve  for adults.  I've seen the same type of scenario with skiing -- many kids pick it up so quickly, and have no fear.