Have you discovered someone already wrote your idea, after writing it?

I wrote sometime ago this idea in a story: there’s a list with the names of the most powerful demons, called barons, everyone knows the names on that list. If you find a baron and their name is not on the list, you have to run. Because if their name is not on the list, is because nobody returned alive to write it down.

Cool, right? Then one day I was reading Frieren at the funeral and found something almost exactly like this. I know nobody writes something 100% original, and everything is already written, but still stings hard when someone already used an idea you loved, and probably did it better.

Anyone got a similar story?