The professional do what they do because of who they are. The creative become who they are because of what they do.
Becoming a creative requires the subtle inversion of cause and effect, at the right time, with the right audience. Rush it, you come off as arrogant. Defer it, you risk of becoming irrelevant.
I believe imposter syndromes signals the arrival of that time for inversion. It is dreadful for all of us, but once you understand what you create next will be your first step towards becoming who you truly are, it becomes the most empowering realization in your life.