I read this book at a time when I had lost my religion which had been very dear to me and the foundation all of my thinking. I was reading lots of different religious texts. This was the first thing I read that said that how we know what we know is more important than what we know. It was the first philosophy I had encountered that would challenge even evidence in favor of itself on the grounds that that evidence didn't meet a certain bar of quality. That was huge and this book helped me understand that concept. Which really made scientific skepticism stand out from other belief systems.