I've thought about it in the converse. Imagine it's just after Einstein releases his paper explaining the theory of special relativity. Given what we know now about it, and it's ramifications, if Einstein truly understood this idea at anything close to this level we do now, how difficult must it have been to explain the bedrock concepts to those first few people that read it. Simply because it was such a radical idea, whether true or not, it must have been a pretty tall order to get his peers on board, as it changed so much about the current understanding of the universe.
I also think in this frame of mind for people like Copernicus, and how controversial his mathematical formulas and expertise must have been, simply because of the magnitude of the sea change that ensued from confirming the ideas.
As I recall, his intuitive insights about special relativity were the easy part. But he had to learn the mathematics required to coherently explain them. There must have been many opportunities for confusion and self doubt.
And that's my point. Just imagine how many times he must have heard some variation on the phrase "Newton has been right this whole time. His laws and ideas are too big to fail"
The accumulation of frustration of not being able to elucidate what is obvious to your inner thoughts, to the satisfaction of your peers, precipitates impostor syndrome.
I also think in this frame of mind for people like Copernicus, and how controversial his mathematical formulas and expertise must have been, simply because of the magnitude of the sea change that ensued from confirming the ideas.