She says the if we start comparing our work to the work of other writers who have gone before, if we start thinking, there's already so much of this kind of fiction out there, what's the use of me writing mine?, that pretty much guarantees we'll quit. Thinking, what does a world that has Shakespeare need with MY love story is just fatal.

It is, and thank you for expressing what I was going to say, only with less elegant language (or Julia Cameron). It's easy to worry yourself to death, thinking you have NOTHING new to say, or that no one will be interested in hearing/reading it. It's a paralysis of creativity.