people have occasionally discovered valuable items hidden in books in real life. Some of the most valuable items found in books include old letters, currency, rare photographs, historical documents, and even small pieces of jewelry.
One famous example is a first edition of Isaac Newton's book "Philosophiæ Naturalis Principia Mathematica" that was discovered in 2016 in a library in the United States. The book was worth millions of dollars.
Additionally, rare book collectors and antique dealers sometimes find valuable bookmarks, autographs, or unique editions hidden within old books. These discoveries can add significant value to the book itself and are considered exciting finds for those interested in rare and valuable collectibles.
If you are curious about valuable items hidden in books, I encourage you to explore some stories of real-life discoveries and treasures found between the pages of old books. However, it's essential to remember that these instances are relatively rare, and most books do not contain valuable hidden items.