I believe that writing truly can bring out the best in an individual. Writing is a way of expressing a persons true, honest thoughts.
I would tell the professor that writing is important to me because it is a main part of the gateway to my future. Without good writing skills, it will be extremely difficult to get a job in any profession.
Writing is important to you (a ten year old) because it is a skill you be using and perfecting for the rest of your life. It is a way of getting your foot in the door of opportunities for your future.