It may surprise you to learn that your education can disect your writing like an autopsy and leave it in nasty pieces all stitches together. I was blessedly lucky to learn this very early in life.
My freshman year in high school I recieved my first creative writing assignment. I will never forget what my English teacher said after I turned it in. He wanted to know if my parents had helped me. I laughed, literally. Writing was definately not my Mom's thing and while my Dad had an amazing imagination, stringing together words on a page was not his strong point. As I laughed I realized my teacher was serious. I assured him they hadn't helped me. He put me on the spot one day in class (I've always thought it was secretly to make sure I was telling the truth) by asking me to describe the statue of liberty using creative writing. I did. He was blown away and the rest of the class didn't want to follow me.
A week later he asked me to stay after class. He explained to me that his class (advanced English) was going to ruin my writing ability and he wanted to take me out of it. I was horrified. I loved English. He explained that he wanted me to sit in the library instead of class everyday and work on a creative writing assignment. I would have to turn a short story in every week. I was in heaven for the rest of high school. Because he was so foreward thinking about my future, I never understood what he meant by 'English class would ruin my writing ability'. Until I took a few classes after high school. I was appalled at how teachers expected me to write.
If you're an aspiring writer and you're in school, take English class with a grain of salt. Or perhaps the whole salt shaker. English is vital to a writer, don't skip out on it. But, know that much of what you learn in that class isn't geared toward creative writing. It is, however, important for building a foundation of good grammar. Here's a great post by the copyblogger on 7 bad writing habits you learned in school: http://www.copyblogger.com/bad-writing-habits/