When you find at least one reader who is able to connect with the message you are trying to relay. Not everyone will like what you do, but as long as they understand where you are coming from, it's all a writer can ask for.
I have always been overly imaginative since a child. I didn't realize I was a writer until seventh grade. I was removed from a special French class for misbehaving and placed in a creative writing group. My teacher was amazed at what came out of me, that she shared it with a colleague. From that moment on, I had the confidence to write whatever my brain conjured up.