I totally agree with Lynn. Ask any instructors of martial arts, dance, music, graphic arts, you name it, and they will all tell you horror stories of students who were fantastically gifted, and quit out of boredom.
Of course, plenty of students also quit because they think that they will never improve.
And, of course, both categories of quitters are wrong.
Let me tell you what has kept me in the martial arts world for almost fifteen years now: stubbornness.