Remember when you were really bad at your job? When you were so awful at your hobby you never figured you'd make a career out of it? Remember, in short, when you were really incompetent?
Treasure those moments.
I'm not talking about treasuring them in a way of puffing yourself up or feeling good about yourself. I'm talking about treasuring these moments because they provide you a valuable insight. You treasure them for what they let you learn about people.
They provide you the ability to sympathize with those less able, less competent, and still learning.
Remember all those times you felt awful? When you thought you'd never make it? Never be able to use those skills you loved to do anything competent? It's almost inevitable that, though you no longer feel that way, you meet many people who feel as bad as you do.
Right now, they're the mirror to who you used to be.
With that experience, you can empathize with them. You can sympathize, relate, and understand. You can help them feel better, be it by talking or simply listening and understanding.
With your knowledge of your own incompetence, you can help them get over theirs. When you can empathize with them, you can then help guide them to becoming better. You can help, not in a condescending way, but in a way that indicates your understanding of their situation.
Finally with your knowledge of your past terrible works, you have a shield against your own arrogance. You were once as bad a writer as the worst fanfic writer, as bad an actor as the worst actor, and you can remember that. You can be protected from your own egotism, and thus make more of a difference.
Enjoy your past incompetence. It'll help people in the future.
– Steven Savage