GEB was what really turned me on to math. I mean, I was good at math by the standards of a mid-tier high school, but was satisfied to work through the problems

GEB was what really turned me on to math. I mean, I was good at math by the standards of a mid-tier high school, but was satisfied to work through the problems and proofs, or use math in my physics class and electronics hobby. But my older brother read GEB then gave it to me. I had also been reading Hofstadter's "Mathematical Games" in Scientific American. But GEB exposed me to a level of math that seemed to beyond puzzles and applications. Or maybe it was just his engaging style. Or my cool big brother. Regardless, I started college as a math major. Other things happened since then, and I now have a physics degree, but still enjoy math as an end unto itself.