Not to mention Lewis Carroll!
Admittedly, I read it in formative years, but until I read GEB, I didn't really grok what "genius" meant. Understanding strange loops in context of great thinkers who expressed it, and seeing strange loops as the nature of consciousness, and wondering how it could be expressed in software... blew my mind, in several senses of the phrase.
I think if your mind isn't changed after reading about these figures, then you haven't really gotten it.
Hofstadter isn't necessarily the main attraction here. He created a framework (ie the structure of the book) where these subjects can be reasoned about.