Have you ever had an idea that you thought was original only to discover that it's already been done before?
This is something I struggle with.
I'll have an idea for a product, or a piece of content, and go on to explore it, but as I progress realize that someone has already written about it or started a company with a similar concept; and I'm stopped dead in my tracks.
This is a deadly phenomenon for any creator, and therefore something that bears understanding.
It seems to stem from a couple of erroneous thoughts:
Instead of letting these ideas rule your actions, maybe it's time to replace them with ones that are closer to the truth.
Answer to 1. If someone has done it, they've validated the idea, and there's always room for a unique take on the idea/product.
Answer to 2. Don't steal, and if you're not, then who cares what people think.
Answer to 3. To make a meaningful contribution to the world, just do something with your perspective, with your creative spin on it, and most of all, create!
Originality and first-to-market can be a strength, but if we let that stop us from taking action, the world would be a rather boring place.