I was sitting on my chair quietly reading when my son bought me the mail, I put it in the back of the book (library book) for save keeping to put away when I got up.

If I had forgotten about it someone would of got a letter when they got this book out of the library.

The question is has anyone found anything interesting in books? Either from the library or secondhand book stores?

I found a grocery list in a library book once... I also found a note that a kid had written to their friend but it didn't make much sense!

Not exactly a treasure: a few weeks ago my sister took out a library book. Until about twelve years ago, before the library was computerized, the librarians used to write the names of the people who took out the book on the book. My sister and I were looking through the names and suddenly she said "look" and pointed at a name: it was the name of a guy from our town who went missing a few years ago as a soldier, and no one knows where he is (it is believed he may be in Syrian custody). It was a rather eerie moment.

My mom taught high school quite a few years back at a place called Walton HS in the Bronx, New York. Around 1966 or so I happened to be helping her get some books from a bookroom at the school to take to her class. In those days (do they do this still?) the books would have a list on the inside cover which each student who used the book had to sign. By utter and total coincidence I picked up a single copy of Tennyson's "Idylls of the King", and found in it the signature of ... Lanni1 !!!!

No, actually it was not Lanni's signature at all. I don't even think Lanni was alive then. What it was, though, was my mom's signature, as she had attended the school about 450 years before, I think shortly after the invention of the printing press. At that point I realized a) that my mom had actually once been a "kid" herself , albeit in medieval times, and b) that Tennyson's poetry would probably be inflicted on ME as well at some point, as indeed it was, about 12 years later. Evil stuff.

I can't say for sure, but I think I actually had a book from that school (Before I thought it was Wagner, but it could be Walton--Then again, it could also be neither.).

Anyhow, it was a textbook on Latin American history or something or another.

I think the most interesting things I've found are a restaurant flier, hall pass, notes, and a postcard from a couple of books I saved from the garbage man a couple of years ago.

I couldn't bring myself to read anything other than the flier and the hall pass. The things were decades old.