I feel like the old schoolmarm saying this, but it’s good advice. I heard this years ago and ignored it while I jumped from project to project, not finishing any of them, which meant I never, ever felt a sense of satisfaction about my work.
I finally completed my first novel three years ago after working on it for five years. I had to learn how to do intensive research efficiently, be ruthless about editing out descriptions and moments I thought were so good but just didn’t fit, stop procrastinating (mostly), and to ignore those demons who sit on my shoulder, whispering I’m not good enough, that no one will want to read anything I’ve written.
But, I finished it and learned there’s a huge difference between wanting to write a novel and actually doing the work to completion. It’s an essential step in becoming a professional writer, but it’s only a step, like getting a black belt in a martial art and your sensei says, now you’re ready to learn.