There are no new ideas.
I've heard this expression many times and I agree, I don't think there are any truly original ideas. When it comes to writing, film-making, drawing, whatever, there really aren't any new ideas. Anything you can think of has already been done, usually a hundred times over.
So what does that mean for you, should you just give up and not bother?
If your idea has already been done, and done well, what could you offer?
This is a problem I often find myself faced with. I'll come up with an idea for a blog post, or an idea for a photo, or something else, and think it's the best I've had in ages. Then I'll find out that someone has already done it. I'll check out their post/photo/other thing and think to myself "I couldn't possibly do it better than that".
My enthusiasm disappears.
The idea I had could've been the best EVER, it could've been the blog post that goes viral, but someone has already done it so why bother...
Well you should bother, and here's why...
Yes, there are no new ideas but the idea that just occurred to you will be coloured by your experiences. The idea itself may be old but the way you interpret that idea is completely unique.
We may all have the same ideas at varying times but each of us have our own way of writing, we each have our own 'voice', our own style. No one can write a blog post the way you would, they can't interpret things the way you do. They are not you.
Just because an idea has been done before does not mean that you shouldn't give it a try.
When you start writing a blog post you add your uniqueness to it, the magic that is 'you' goes into every post. Your experiences and memories colour every idea, making all of your ideas unique.
Your view of the world is no less valid than someone else's.
Perhaps you'll improve on the original idea.
Perhaps you'll have a different interpretation.
Either way, do not be afraid to try something just because it's been done before.
No one else could express the idea the way you will.
So, go on, take the chance.