By "writing" I mean composing. You should be creating with every moment you are at the keyboard. Music is indeed a language, with all the subtlety and nuance and any language has, and mastering it is every bit as difficult as mastering any language, but it's made easier by immersing yourself in it. Whether you are playing your own music or another person's, you are creating the tones and the emotion of that piece, and it helps to use your imagination. If you look at piano as merely pressing buttons in the right order so that your teacher may be pleased, that's pretty sad and boring. And your playing will have no point.If you look at music simply as dots on a piece of paper, then physically writing a lot will simply improve only your penmanship. As a side note (or maybe it's my main point....), classical music is more than just reading. Just like acting is more than reading. The written form is the most convenient way to pass along the information, but there's far more to it than just puking the notes back out correctly. Interpretation is like creating the composer's music, although each of us is a filter.Now I'm rambling........