When Can You Call Yourself a Writer?

It took me ages to be able to call myself a writer. It was probably about five years after my first book was published that I managed to answer a question about my occupation with those four small but loaded words; "I am a writer". And, despite being traditionally published, despite having my first children's book taken from the slush pile by Puffin, I felt like a massive fraud. I think this is partly because most people are so interested in writers, impressed even and thank-goodness they are...