The discussion centers on recommendations for books suitable for someone who has completed math classes up to Calculus I, specifically after reading "Exploring Black Holes" by Taylor and Wheeler. A notable suggestion is "Introduction to Calculus and Analysis, Volume I" by Richard Courant and Fritz John, which is priced at $40 and is available in libraries. The book covers essential topics such as differentiation, integration, infinite sequences, and applications to physics, making it a good fit for someone interested in deepening their understanding of calculus. There is some debate about whether the material in the book aligns with what is typically covered in a one-semester Calculus I course, particularly regarding hyperbolic functions and series. Additionally, the lack of answer keys for problems in the book is discussed, with the consensus that the book's depth compensates for this. It is suggested that readers may also benefit from an introductory book on mathematical proofs to enhance their understanding.