This is a video of a girl learning to dance in one year.  In the beginning, we see her attempting basic moves.  As the video progresses, we see her progress.  By the end, she is incredible.

The girl in the video is Karen Cheng.  She says she practiced everyday.  Karen explains, " I practiced everywhere. At bus stops. In line at the grocery store. At work — Using the mouse with my right hand and practicing drills with my left hand. You don't have to train hardcore for years to become a dancer. But you must be willing to practice and you better be hungry."

Watch it.