Well, I'm sure that when you think back, you can identify a major influence on your development as a writer. Perhaps it was a teacher, a colleague, a particular project.
For me, it has always been the "challenging" reviewers, the people who read my prose with a very different perspective than what I had in mind while writing it. They help me understand different ways of learning, different interpretations of words, and many ways to presents my ideas with greater clarity and interest.
Who or what has been your greatest influence as a writer? Share your stories here; I'm sure we will all learn from your experience.