Did those original thoughts not build upon all the original thoughts that came before them?

Sure they build upon them, you still need to add your 1% of original insight. There was a first person to realise that you could make fire by rubbing two sticks together.

Is my house a copy of the dirt it's on top of? Did the people who built my house build the dirt? There's a difference between "building upon" an idea and trying to claim you built the idea itself