A friend of mine tweeted that he's embarrassed to only recently discover the Mac shortcut for displaying the emoji keyboard: Ctrl-Cmd-Space.
His embarrassment stems from the assumption that other people have known about this shortcut way before him.
I would guess that many of his followers (and many of my readers here) didn't know about this shortcut before we mentioned it.
It's easy to assume that what we know is common knowledge.
This makes us feel like whatever we can contribute to others isn't worth contributing. They already know what we know.
Even if there are many people who already knew it, it's new to those who don't.
There will always be people who already know the idea you want to share, and there will always be people who don't yet know it. Don't the existence of the first group make you overlook the existence of the second group. Bring your attention to the second group.
I see this attitude a lot when I coach community members struggling with impostor syndrome or when they are hesitant about giving training courses to others. They start to compare themselves to experts, and end up asking themselves: "Who am I to be giving this workshop?"
In return, I ask them: "Are there people who don't know what you know that you can help them by sharing what you know?"
The answer is always yes.
Never shy away from sharing.