This is intended as a very abstract philosophical question.
Like Einstein with relativity was inspired by a man falling from a roof and a moving train. Most creative ideas seem to boil down to a person moving ideas across domains. Do you think this is always true even if the person is unwilling to admit the root thoughts, or perhaps they are completely unaware of the connections they subconsciously made? Is there truly a provably unique thought or is everything a product of experience?
Counter point: Is human existence unique and separate from the universe we live in? If you can influence someone’s thoughts by changing their brain chemistry then how separate from our surroundings are we?