If you are asking yourself (and your friends), "Am I really a writer? Am I really an artist? Chances are, you are. The counterfeit innovator is wildly self-confident. The real one is scared to death." (Steven Pressfield, The Art of War)
Warning- Writer At Work! By Penalty of death of your favorite character do not enter except in case of real emergency. Things that constitute a real emergency; the house is on fire, the zombie apocalypse has begun, lunch is ready.