I would personally recommend The Princeton Companion to Mathematics as an excellent introduction to mathematics from someone no pursuing a degree. See https://

I would personally recommend The Princeton Companion to Mathematics as an excellent introduction to mathematics from someone no pursuing a degree. See https://press.princeton.edu/books/hardcover/9780691118802/the-princeton-companion-to-mathematics https://press.princeton.edu/books/hardcover/9780691118802/th...