"Some kids have it, some kids don't," as my brother's high school math teacher once said. It's the same thing I realized when I went to work at a radio station many years ago -- I picked everything up in a couple of weeks, but the guy who was the program director had been on the radio for 15 years and still stunk. If you've got it, you can pick whatever it is up in very little time, but if you don't, it doesn't matter how long you do it, you'll never be any good. If you've got some seeds of "it", lots of practice can make you serviceable at something, but probably not great. Now, if they had wanted me to learn to MAKE music instead of playing it on records, it wouldn't have mattered how long they gave me -- I'm not musical, and I never will be, and 10,000 hours of practice would not help.
I have a Dilbert cartoon in my desk collection:
Dilbert: "Studies show it takes ten thousand hours of practice to be great at anything."
Dogbert: "I would think a willingness to practice the same thing for ten thousand hours is a mental disorder."
Dilbert: "That makes me feel better about my mediocrity."
Dogbert: "You're welcome."
