It's true... originality is tough. It seems the best we can ever do is a different combination of things that have already been done before. :/
My last original Idea got me C+ :( And it's true, I mostly find my original ideas have been already presented
I have original ideas all the time. But I don't think it matters if someone else has thought of it already. It's original to you, as long as you haven't heard it before. Makes it no less creative and brilliant than the first person to think of it.