I stumbled on Q.E.D by Feynman at a young age - it had a deep influence on me. I also read parts of "the mathematical experience" by Davis and Hersch, and "Gode

I stumbled on Q.E.D by Feynman at a young age - it had a deep influence on me. I also read parts of "the mathematical experience" by Davis and Hersch, and "Godel, Escher, Bach" by Douglas Hofstadter. It's not really maths, but Spacetime Physics: Introduction to Special Relativity would have been great for me at that age. The Princeton Companion is a cool book, but it'd be better suited to a graduate in mathematics.